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    Reconstitution of Th17, Tc17 and Treg cells after paediatric haematopoietic stem cell transplantation: Impact of interleukin-7. Kielsen Katrine,Ryder Lars P,Lennox-Hvenekilde David,Gad Monika,Nielsen Claus H,Heilmann Carsten,Ifversen Marianne,Pedersen Anders Elm,Müller Klaus Immunobiology Successful reconstitution of T lymphocytes after allogeneic haematopoietic stem cell transplantation (HSCT) is needed to establish the graft-versus-leukaemia effect and an effective anti-microbial defense, but the ratio between functionally different T-cell subsets needs to be balanced to avoid graft-versus-host disease (GVHD). IL-7 is essential for T-cell generation in the thymus and peripheral T-cell homeostasis. High IL-7 levels have been associated with impaired T-cell reconstitution, increased risk of acute GVHD and treatment-related mortality, but the underlying cellular mechanisms behind these associations have not been investigated previously. We hypothesized that increased levels of IL-7 post-transplant alters the balance between immune-regulatory T cell subsets during the post-transplant lymphocyte recovery towards a more pro-inflammatory profile. We quantified Th17 cells, Tc17 cells and Tregs in 29 children following HSCT. Th17 cell and Treg counts rose significantly from day +90 to +180 post-HSCT, and prior acute GVHD was associated with significant changes in the concentration of Tregs (9.4×10/L vs. 1.3×10/L, P=0.0052) and the Th17/Treg ratio (1.5 vs. 4.2, P=0.025). The plasma level of IL-7 at day +90 correlated inversely with Th17 cell counts (r=-0.65, P=0.0002) and the proportion of Tc17 cells (r=0.64, P=0.0005) at day +90, but not with Tregs. Furthermore, high IL-7 levels at day +7 were predictive of a less naïve T-cell phenotype at day +90. These findings add further evidence that IL-7 is a key regulatory factor that may tune the balance between functionally different T-cell subsets following HSCT. 10.1016/j.imbio.2017.10.023
    Enumeration of bone marrow plasmacytoid dendritic cells by multiparameter flow cytometry as a prognostic marker following allogeneic hematopoietic stem cell transplantation. Su Ruijun Jeanna,Green Ralph,Chen Mingyi Blood cells, molecules & diseases Plasmacytoid dendritic cells (pDCs) promote tolerance in solid organ transplants and hematopoietic stem cell transplantation (HSCT). pDCs originate from CD34 hematopoietic progenitors. Following allogeneic hematopoietic stem cell transplant (allo-HSCT), pDC reconstitution in the BM and PB gradually attain levels similar to those in healthy individuals. We have investigated the recovery of pDC following allo-HSCT as a means to predict successful marrow engraftment. We retrospectively studied immune reconstitution of pDC in the BM of 48 patients following allo-HSCT for initial diagnoses of leukemia or other malignancies. Multi-parameter flow cytometry was used to detect the CD45CD123 HLA-DR CD4 pDCs in BM aspirates at 2-14months (median 6months) post allo-HSCT. Percentages of pDCs were analyzed along with engraftment, acute graft-versus-host disease (aGVHD), event-free survival, relapse and death over a period of up to 39months (median 30) following HSCT. We report that higher levels of pDCs in the BM post-HSCT are associated with successful engraftment, less severity of aGVHD, lower relapse rate, higher event-free survival and overall survival (P value <0.05 for all). pDC levels detected at a shorter time interval 2-8months (median 5months) following HSCT also showed similar results. We conclude that pDC numbers are associated with HSCT engraftment and overall survival. Flow cytometry offers rapid quantification of pDCs as an early predictor of outcome following HSCT. 10.1016/j.bcmd.2017.10.004
    Dynamics of genetically engineered hematopoietic stem and progenitor cells after autologous transplantation in humans. Scala Serena,Basso-Ricci Luca,Dionisio Francesca,Pellin Danilo,Giannelli Stefania,Salerio Federica Andrea,Leonardelli Lorena,Cicalese Maria Pia,Ferrua Francesca,Aiuti Alessandro,Biasco Luca Nature medicine Hematopoietic stem and progenitor cells (HSPC) are endowed with the role of generating and maintaining lifelong the extremely diverse pool of blood cells. Clinically, transplantation of human HSPC from an allogeneic healthy donor or infusion of autologous gene-corrected HSPC can effectively replenish defective blood cell production caused by congenital or acquired disorders. However, due to methodological and ethical constraints that have limited the study of human HSPC primarily to in vitro assays or xenotransplantation models, the in vivo activity of HSPC has to date remained relatively unexplored in humans. Here we report a comprehensive study of the frequencies, dynamics and output of seven HSPC subtypes in humans that was performed by tracking 148,093 individual clones in six patients treated with lentiviral gene therapy using autologous HSPC transplantation and followed for up to 5 years. We discovered that primitive multipotent progenitor and hematopoietic stem cell (HSC) populations have distinct roles during the initial reconstitution after transplant, compared with subsequent steady-state phases. Furthermore, we showed that a fraction of in vitro-activated HSC are resilient and undergo a defined delayed activation period upon transplant. Finally, our data support the concept that early lymphoid-biased progenitors might be capable of long-term survival, such that they can be maintained independently of their continuous production from HSC. Overall, this study provides comprehensive data on HSPC dynamics after autologous transplantation and gene therapy in humans. 10.1038/s41591-018-0195-3
    Third party, umbilical cord blood derived regulatory T-cells for prevention of graft versus host disease in allogeneic hematopoietic stem cell transplantation: feasibility, safety and immune reconstitution. Kellner Joshua N,Delemarre Eveline M,Yvon Eric,Nierkens Stefan,Boelens Jaap J,McNiece Ian,Olson Amanda,Nieto Yago,Ciurea Stefan,Popat Uday,Ahmed Sairah,Champlin Richard,Ramos Jennifer,Nishimoto Mitsutaka,Ma Hongbing,Ke Zeng,Thall Peter,Khoury Joseph D,Negrin Robert,Andersson Borje,Parmar Simrit Oncotarget Incubation of umbilical cord blood (UCB) derived regulatory T-cells (Tregs) with fucosyltransferase enzyme improves their ability to home to the target tissue to prevent graft vs. host disease (GVHD). We report results of 5 patients (Double UCB Transplant, n=2; Peripheral Blood Matched Unrelated Donor Transplant, n=3) who received UCB-Tregs (Dose level = 1×106/kg), infused one day prior to the donor graft. All patients received their designated UCB-Treg dose without any infusion reaction. The ratio of conventional T-cells in donor graft was at least 10 times higher than infused UCB-Tregs (ratio range, 12-356). All patients engrafted at median of 13 days (range, 8-17 days). One patient died due to brain hemorrhage on day 45. A bi-modal increase of plasma IL-10 level occurred on day 7 and day 21 and notably, plasma IL-2 level dropped significantly in all patients at Day 7. All evaluable patients developed ≥grade II acute GVHD and at 1 year follow up, all were alive and without evidence of disease relapse. No increase in the chronic GVHD biomarkers (REG3a and Elafin) was observed at day 7. At the time of last follow up, all evaluable patients were off immune-suppression. Stage 2 of this clinical trial examining UCB-Treg at dose level= 1×107/kg is currently underway. 10.18632/oncotarget.26242
    Resetting the T Cell Compartment in Autoimmune Diseases With Autologous Hematopoietic Stem Cell Transplantation: An Update. Lutter Lisanne,Spierings Julia,van Rhijn-Brouwer Femke C C,van Laar Jacob M,van Wijk Femke Frontiers in immunology Autologous hematopoietic stem cell transplantation (aHSCT) for autoimmune diseases has been applied for two decades as a treatment for refractory patients with progressive disease. The rationale behind aHSCT is that high-dose immunosuppression eliminates autoreactive T and B cells, thereby resetting the immune system. Post-aHSCT the cytotoxic CD8 T cells normalize clonal expansion due to homeostatic proliferation within a few months. CD4 T cells recover primarily thymopoiesis resulting in complete renewal of the T cell receptor (TCR) repertoire which requires years or never normalize completely. The increase in naïve T cells inducing immune tolerance, renewal of especially the regulatory TCR repertoire, and a less pro-inflammatory functional profile of the CD4 T cells seem essential for successful immune reconstitution inducing long-term remission. There is currently a knowledge gap regarding the immune response in tissue sites post-aHSCT, as well as disease-specific factors that may determine remission or relapse. Future studies on lymphocyte dynamics and function may pave the way for optimized conditioning regimens with a more individualized approach. 10.3389/fimmu.2018.00767
    Mass Cytometry and Topological Data Analysis Reveal Immune Parameters Associated with Complications after Allogeneic Stem Cell Transplantation. Lakshmikanth Tadepally,Olin Axel,Chen Yang,Mikes Jaromir,Fredlund Erik,Remberger Mats,Omazic Brigitta,Brodin Petter Cell reports Human immune systems are variable, and immune responses are often unpredictable. Systems-level analyses offer increased power to sort patients on the basis of coordinated changes across immune cells and proteins. Allogeneic stem cell transplantation is a well-established form of immunotherapy whereby a donor immune system induces a graft-versus-leukemia response. This fails when the donor immune system regenerates improperly, leaving the patient susceptible to infections and leukemia relapse. We present a systems-level analysis by mass cytometry and serum profiling in 26 patients sampled 1, 2, 3, 6, and 12 months after transplantation. Using a combination of machine learning and topological data analyses, we show that global immune signatures associated with clinical outcome can be revealed, even when patients are few and heterogeneous. This high-resolution systems immune monitoring approach holds the potential for improving the development and evaluation of immunotherapies in the future. 10.1016/j.celrep.2017.08.021
    Rapid Recovery of CD3+CD8+ T Cells on Day 90 Predicts Superior Survival after Unmanipulated Haploidentical Blood and Marrow Transplantation. Tian Deng-Mei,Wang Yu,Zhang Xiao-Hui,Liu Kai-Yan,Huang Xiao-Jun,Chang Ying-Jun PloS one BACKGROUND:Rapid immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is significantly associated with lower infection, relapse and possibly secondary malignancy rates. The aim of this study was to investigate the role of peripheral lymphocyte subsets, especially CD3+CD8+ cytotoxic T cell recovery, in predicting transplant outcomes, including the overall survival (OS) and non-relapse mortality (NRM) rates after unmanipulated haploidentical blood and marrow transplantation (HBMT). METHODS:Peripheral blood samples were obtained from 214 HBMT recipients with hematological malignancies. The peripheral lymphocyte subsets (CD3+ T cells, CD3+CD4+ helper T cells, CD3+CD8+ cytotoxic T cells, and CD19+ B cells) were analyzed by flow cytometry at days 30, 60, 90, 180, 270 and 360 after HBMT. RESULTS:The CD3+CD8+ cytotoxic T cell recovery at day 90 (CD3+CD8+-90) was correlated with bacterial infection (P = 0.001), NRM (P = 0.001), leukemia-free survival (LFS, P = 0.005), and OS (P = 0.001) at a cutoff value of 375 cells/μL CD3+CD8+ T cells. The incidence of bacterial infection in patients with the CD3+CD8+-90 at ≥375 cells/μL was significantly lower than that of cases with the CD3+CD8+-90 at <375 cells/μL after HBMT (14.6% versus 41.6%, P<0.001). Multivariate analysis showed the rapid recovery of CD3+CD8+ T cells at day 90 after HBMT was strongly associated with a lower incidence of NRM (HR = 0.30; 95% CI: 0.15-0.60; P = 0.000) and superior LFS (HR = 0.51; 95% CI: 0.32-0.82; P = 0.005) and OS (HR = 0.38; 95% CI: 0.23-0.63; P = 0.000). CONCLUSION:The results suggest that the rapid recovery of CD3+CD8+ cytotoxic T cells at day 90 following HBMT could predict superior transplant outcomes. 10.1371/journal.pone.0156777
    [Relationship between NK Cell Reconstitution and aGVHD after Allo-HSCT]. Wan Lu-Lu,Chen Jian-Lin,Xu Chen,Li Bo-Tao,Hu Jiang-Wei,Lou Xiao,Yang Fan,Liu Na,Su Yong-Feng,Lan San-Chun,Wang Qing-Han,Qiao Zhuo-Qing,Wang Lei,Jiang Min,Li Yu-Hang,Hu Liang-Ding Zhongguo shi yan xue ye xue za zhi OBJECTIVE:To investigate the relationship between NK cell count/activity and acute graft-versus-host disease (aGVHD) in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS:A total of 26 patients who had undergone allo-HSCT from January to July 2015 were enrolled in this study. The NK cell count/activity in the peripheral blood of recipients on day 30 after allo-HSCT were monitored by using 4-color flow cytometry. The incidence of aGVHD in patients was evaluated by clinical manifestation combinating with related pathologic indicators, and the relationship between NK cell count/activity and aGVHD were analyzed. RESULTS:In the aGVHD group and the no-aGVHD group, the NK cell count and activity on days 30 after allo-HSCT were 655±216 cells/µl vs 1169±372 cells/µl(P=0.002) and 7.3±3.6% vs 9.0±3.6% (P=0.008). In the II-IV grade aGVHD group and the 0-I grade aGVHD group, the NK cell count/activity were 617±220 cells/µl vs 1081±399 cells/µl (P=0.001) and 4.2±1.7% vs 8.3±3.5%(P=0.001). As compared with the 0-I grade aGVHD group, patients in the II-IV grade aGVHD group had higher relapse rate (57% vs 5%)(P=0.010) , lower 1-year progression-free survival(PFS) rate (43% vs 84%)(P=0.010). CONCLUSION:NK cell count/activity on day 30 after allo-HSCT were closely relates with aGVHD, which may be a potential marker for aGVHD and can provide a new target for aGVHD therapy. 10.7534/j.issn.1009-2137.2017.02.040
    The First 90 Days: Temporary Effect of Alemtuzumab on CMV Immune Reconstitution. Abate Davide Transplantation 10.1097/TP.0000000000001598
    Altered immune reconstitution of B and T cells precedes the onset of clinical symptoms of chronic graft-versus-host disease and is influenced by the type of onset. Bohmann E-M,Fehn U,Holler B,Weber D,Holler E,Herr W,Hoffmann P,Edinger M,Wolff D Annals of hematology We analyzed lymphocyte subpopulations and cytokines 3 months after allogeneic hematopoietic stem cell transplantation aiming to identify predictive cellular and serum markers for chronic graft-versus-host disease (cGVHD). Samples of 49 patients (pts) (no cGVHD (n = 14), subsequent quiescent onset (n = 16), de novo onset of cGVHD (n = 19)) were analyzed in the absence of active GVHD by flow cytometry and enzyme-linked immunosorbent assay. All mean absolute cell counts are presented as cells per microliter; relative cell counts are presented as percentage of lymphocytes. Pts with subsequent de novo cGVHD had significantly higher relative and absolute counts of CD4+ T cells including higher absolute counts of CD4+ memory T cells (22.36%; 206.55/μl; 136/μl, respectively) compared to pts with subsequent quiescent onset of cGVHD (12.41%; 83.42/μl; 54.3/μl) and pts without cGVHD (10.55%) with regard to relative counts of CD4+ T cells. Similarly, significantly more relative and absolute regulatory T cell numbers (CD4+FOXP3+) were detected in pts with de novo onset of cGVHD (3.08% and 24.63/μl) compared to those in pts without (1.25% and 9.06/μl) or with quiescent onset of cGVHD (1.15% and 6.91/μl). Finally, relative B cell counts, including naïve and memory B cells, were also significantly decreased in pts developing quiescent cGVHD (0.85, 0.73, 0.12% resp.) when compared to pts with de novo onset (5.61, 5.24, 0.38%). The results demonstrate that alterations in immune reconstitution are already present before onset of clinical symptoms and differ between de novo and quiescent onset of disease. 10.1007/s00277-016-2881-x
    T cell repertoire remodeling following post-transplant T cell therapy coincides with clinical response. Smith Corey,Corvino Dillon,Beagley Leone,Rehan Sweera,Neller Michelle A,Crooks Pauline,Matthews Katherine K,Solomon Matthew,Le Texier Laetitia,Campbell Scott,Francis Ross S,Chambers Daniel,Khanna Rajiv The Journal of clinical investigation BACKGROUNDImpaired T cell immunity in transplant recipients is associated with infection-related morbidity and mortality. We recently reported the successful use of adoptive T cell therapy (ACT) against drug-resistant/recurrent cytomegalovirus in solid-organ transplant recipients.METHODSIn the present study, we used high-throughput T cell receptor Vβ sequencing and T cell functional profiling to delineate the impact of ACT on T cell repertoire remodeling in the context of pretherapy immunity and ACT products.RESULTSThese analyses indicated that a clinical response was coincident with significant changes in the T cell receptor Vβ landscape after therapy. This restructuring was associated with the emergence of effector memory T cells in responding patients, while nonresponders displayed dramatic pretherapy T cell expansions with minimal change following ACT. Furthermore, immune reconstitution included both adoptively transferred clonotypes and endogenous clonotypes not detected in the ACT products.CONCLUSIONThese observations demonstrate that immune control following ACT requires significant repertoire remodeling, which may be impaired in nonresponders because of the preexisting immune environment. Immunological interventions that can modulate this environment may improve clinical outcomes.TRIAL REGISTRATIONAustralian New Zealand Clinical Trial Registry, ACTRN12613000981729.FUNDINGThis study was supported by funding from the National Health and Medical Research Council, Australia (APP1132519 and APP1062074). 10.1172/JCI128323
    Functional Reconstitution of Natural Killer Cells in Allogeneic Hematopoietic Stem Cell Transplantation. Ullah Md Ashik,Hill Geoffrey R,Tey Siok-Keen Frontiers in immunology Natural killer (NK) cells are the first lymphocyte population to reconstitute following allogeneic hematopoietic stem cell transplantation (HSCT) and are important in mediating immunity against both leukemia and pathogens. Although NK cell numbers generally reconstitute within a month, the acquisition of mature NK cell phenotype and full functional competency can take 6 months or more, and is influenced by graft composition, concurrent pharmacologic immunosuppression, graft-versus-host disease, and other clinical factors. In addition, cytomegalovirus infection and reactivation have a dominant effect on NK cell memory imprinting following allogeneic HSCT just as it does in healthy individuals. Our understanding of NK cell education and licensing has evolved in the years since the "missing self" hypothesis for NK-mediated graft-versus-leukemia effect was first put forward. For example, we now know that NK cell "re-education" can occur, and that unlicensed NK cells can be more protective than licensed NK cells in certain settings, thus raising new questions about how best to harness graft-versus-leukemia effect. Here, we review current understanding of the functional reconstitution of NK cells and NK cell education following allogeneic HSCT, highlighting a conceptual framework for future research. 10.3389/fimmu.2016.00144
    NK cells produce high levels of IL-10 early after allogeneic stem cell transplantation and suppress development of acute GVHD. Chan Yuen Ling Tracey,Zuo Jianmin,Inman Charlotte,Croft Wayne,Begum Jusnara,Croudace Joanne,Kinsella Francesca,Maggs Luke,Nagra Sandeep,Nunnick Jane,Abbotts Ben,Craddock Charles,Malladi Ram,Moss Paul European journal of immunology Natural killer (NK) cells rapidly reconstitute following allogeneic stem cell transplantation (allo-SCT), at the time when alloreactive T cell immunity is being established. We investigated very early NK cell reconstitution in 82 patients following T cell-depleted allo-SCT. NK cell number rapidly increased, exceeding T cell reconstitution such that the NK:T cell ratio was over 40 by day 14. NK cells at day 14 (NK-14) were donor-derived, intensely proliferating and expressed chemokine receptors targeted to lymphoid and peripheral tissue. Spontaneous production of the immunoregulatory cytokine IL-10 was observed in over 70% of cells and transcription of cytokines and growth factors was augmented. NK-14 cell number was inversely correlated with the incidence of grade II-IV acute graft versus host disease (GVHD). These findings reveal that robust reconstitution of immunoregulatory NK cells by day 14 after allo-SCT is an important determinant of the clinical outcome, suggesting that NK cells may suppress the development of the T cell-mediated alloreactive immune response through production of IL-10. 10.1002/eji.201747134
    CMV-Reactive NK Cells in Pediatric Post-Hematopoietic Stem Cell Transplant. Apiwattanakul Nopporn,Hongeng Suradej,Anurathapan Usanarat,Pakakasama Samart,Srisala Supanart,Klinmalai Chompunuch,Andersson Borje S Transplantation proceedings BACKGROUND:Immune reconstitution of T cells has been proven to be a protective factor against cytomegalovirus (CMV) reactivation in patients post-hematopoietic stem cell transplant. Recently, more evidence has suggested that natural killer (NK) cells also play role in the protection against CMV reactivation in these patients. METHODS:CMV-specific T cells and CMV-reactive NK cells from pediatric patients undergoing hematopoietic stem cell transplant were examined by flow cytometry. These cells were defined as cells producing interferon gamma (IFNγ) upon stimulation with CMV antigens. RESULTS:This study demonstrated that NK cells reactive to CMV do exist in pediatric patients after stem cell transplant. These cells vigorously responded to stimulation with CMV peptides (pp65 and IE1) and to a lesser extent to CMV whole lysate by secretion of IFNγ. Patients with CMV reactivation tended to have less CMV-reactive NK cells than those without. CONCLUSION:Reconstitution of CMV-reactive NK cells, together with CMV-specific T cells, may play a role in the control of CMV infections in patients after stem cell transplant. 10.1016/j.transproceed.2019.11.010
    Optimal Threshold and Time of Absolute Lymphocyte Count Assessment for Outcome Prediction after Bone Marrow Transplantation. Bayraktar Ulas D,Milton Denái R,Guindani Michele,Rondon Gabriela,Chen Julianne,Al-Atrash Gheath,Rezvani Katayoun,Champlin Richard,Ciurea Stefan O Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation The recovery pace of absolute lymphocyte count (ALC) is prognostic after hematopoietic stem cell transplantation. Previous studies have evaluated a wide range of ALC cutoffs and time points for predicting outcomes. We aimed to determine the optimal ALC value for outcome prediction after bone marrow transplantation (BMT). A total of 518 patients who underwent BMT for acute leukemia or myelodysplastic syndrome between 1999 and 2010 were divided into a training set and a test set to assess the prognostic value of ALC on days 30, 60, 90, 120, 180, as well as the first post-transplantation day of an ALC of 100, 200, 300, 400, 500, and 1000/μL. In the training set, the best predictor of overall survival (OS), relapse-free survival (RFS), and nonrelapse mortality (NRM) was ALC on day 60. In the entire patient cohort, multivariable analyses demonstrated significantly better OS, RFS, and NRM and lower incidence of graft-versus-host disease (GVHD) in patients with an ALC >300/μL on day 60 post-BMT, both including and excluding patients who developed GVHD before day 60. Among the patient-, disease-, and transplant-related factors assessed, only busulfan-based conditioning was significantly associated with higher ALC values on day 60 in both cohorts. The optimal ALC cutoff for predicting outcomes after BMT is 300/μL on day 60 post-transplantation. 10.1016/j.bbmt.2015.10.020
    Homeostatic cytokines in immune reconstitution and graft-versus-host disease. Thiant Stéphanie,Moutuou Moutuaata M,Leboeuf Dominique,Guimond Martin Cytokine For numerous patients, allogeneic stem cell transplantation (SCT) is the only therapeutic option that could potentially cure their disease. Despite significant progress made in clinical management of allogeneic SCT, acute graft-versus-host disease (aGVHD) remains the second cause of death after disease recurrence. aGVHD is highly immunosuppressive and the adverse effect of allogeneic SCT on T cell regeneration is typically more important than the levels of immunosuppression normally seen after autologous SCT. In these patients, immune reconstitution often takes several years to occur and restoring immunocompetence after allogeneic SCT represents an important challenge, principally because clinical options are limited and current methods used to accelerate immune reconstitution are associated with increased GVHD. Interleukin-7 and IL-15 are both under clinical investigation and demonstrate the greatest potential on peripheral T cells regeneration in mice and humans. However, awareness has been raised about the use of IL-7 and IL-15 after allogeneic SCT with regards to potential adverse effects on aGVHD. In this review, we will discuss about recent progress made in lymphocyte regeneration, the critical role played by IL-7 and IL-15 in T cell homeostasis and how these cytokines could be used to improve immune reconstitution after allogeneic SCT. 10.1016/j.cyto.2016.01.003
    Autologous Adoptive T-cell Therapy for Recurrent or Drug-resistant Cytomegalovirus Complications in Solid Organ Transplant Recipients: A Single-arm Open-label Phase I Clinical Trial. Smith Corey,Beagley Leone,Rehan Sweera,Neller Michelle A,Crooks Pauline,Solomon Matthew,Holmes-Liew Chien-Li,Holmes Mark,McKenzie Scott C,Hopkins Peter,Campbell Scott,Francis Ross S,Chambers Daniel C,Khanna Rajiv Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Background:Opportunistic infections including cytomegalovirus (CMV) are a major cause of morbidity and mortality in solid organ transplant (SOT) recipients. The recurrent and protracted use of antiviral drugs with eventual emergence of drug resistance represents a significant constraint to therapy. Although adoptive T-cell therapy has been successfully used in hematopoietic stem cell transplant recipients, its extension to the SOT setting poses a considerable challenge because of the inhibitory effects of immunosuppressive drugs on the virus-specific T-cell response in vivo and the perceived risk of graft rejection. Methods:In this prospective study, 22 SOT recipients (13 renal and 8 lung and 1 heart transplants) with recurrent or ganciclovir-resistant CMV infection were recruited, and 13 of them were treated with in vitro-expanded autologous CMV-specific T cells. These patients were monitored for safety, clinical symptoms, and immune reconstitution. Results:Autologous CMV-specific T-cell manufacture was attempted for 21 patients, and was successful in 20. The use of this adoptive immunotherapy was associated with no therapy-related serious adverse events. Eleven (84%) of the 13 treated patients showed improvement in symptoms, including complete resolution or reduction in DNAemia and CMV-associated end-organ disease and/or the cessation or reduced use of antiviral drugs. Furthermore, four of these patients showed coincident increased frequency of CMV-specific T cells in peripheral blood after completion of T-cell therapy. Conclusions:The data presented here demonstrate for the first time the clinical safety of CMV-specific adoptive T-cell therapy and its potential therapeutic benefit for SOT recipients with recurrent and/or drug-resistant CMV infection or disease. Clinical Trials Registration:ACTRN12613000981729. 10.1093/cid/ciy549
    Comparison of reference values for immune recovery between event-free patients receiving haploidentical allografts and those receiving human leukocyte antigen-matched sibling donor allografts. Pei Xuying,Zhao Xiangyu,Wang Yu,Xu Lanping,Zhang Xiaohui,Liu Kaiyan,Chang Yingjun,Huang Xiaojun Frontiers of medicine To establish optimal reference values for recovered immune cell subsets, we prospectively investigated post-transplant immune reconstitution (IR) in 144 patients who received allogeneic stem cell transplantation (allo- SCT) and without showing any of the following events: poor graft function, grades II‒IV acute graft-versus-host disease (GVHD), serious chronic GVHD, serious bacterial infection, invasive fungal infection, or relapse or death in the first year after transplantation. IR was rapid in monocytes, intermediate in lymphocytes, CD3 Tcells, CD8 T cells, and CD19 B cells, and very slow in CD4 T cells in the entire patient cohort. Immune recovery was generally faster under HLA-matched sibling donor transplantation than under haploidentical transplantation. Results suggest that patients with an IR comparable to the reference values display superior survival, and the levels of recovery in immune cells need not reach those in healthy donor in the first year after transplantation.We suggest that data from this recipient cohort should be used as reference values for post-transplant immune cell counts in patients receiving HSCT. 10.1007/s11684-017-0548-1
    Leukemia-free survival in myeloid leukemia, but not in lymphoid leukemia, is predicted by early CD4+ reconstitution following unrelated cord blood transplantation in children: a multicenter retrospective cohort analysis. Admiraal R,Chiesa R,Lindemans C A,Nierkens S,Bierings M B,Versluijs A B,Hiwarkar P,Furtado Silva J M,Veys P,Boelens J J Bone marrow transplantation 10.1038/bmt.2016.116
    Hematopoietic stem cell transplantation with alpha/beta T-lymphocyte depletion and short course of eculizumab in adolescents and young adults with paroxysmal nocturnal hemoglobinuria. Shasheleva D A,Maschan A A,Shelikhova L N,Petrova U N,Kurnikova E E,Illarionova O I,Boyakova E V,Novichkova G A,Maschan M A Terapevticheskii arkhiv AIM:The main goal is to optimize hematopoietic stem cell transplantation (HSCT) approach among adolescents and young adults with paroxysmal nocturnal hemoglobinuria (PNH) by means of Graft-versus-host disease (GVHD) and post-transplant complications risk lowering. MATERIALS AND METHODS:We report our experience of HSCT from HLA-matched unrelated donors using TCR alfa/beta and CD19 depletion in 5 pts (1M/4F) with PNH, developed after successful immunosuppressive therapy (IST) of acquired aplastic anemia (AA). Median age of pts at the moment of transplantation was 17,8 years (range 14,5-22,7), median interval from IST to PNH was 4 years (5mo - 6,5 y). In all patients non-severe pancytopenia was present: granulocytes 0,8х109/l (0,8-1,8 х109/l) platelets 106 х109/l (27-143 х109/l) and Hb -78 g/l, median PNH clone size in granulocytes was 94 (range 75-99)%. One pts previously developed sinus thrombosis. Conditioning consisted of thoraco-abdominal irradiation 4-6 Gy, cyclophosphamide 100 mg/kg, fludarabine 150 mg/m2 and anti-thymocyte globulin (ATG) or alemtuzumab. Eculizumab was given from day (-7) till day (+14) (every 7 days, only 4 times). GVHD prophylaxis was tacrolimus ± methotrexate. RESULTS:Infusedgraft characteristics were: CD34+ - 8,1х106/kg, CD3TCRab·150х103/kg, CD3gd+ - 7,3х106/kg, СD19+ - 221х103/kg, NK -6,4х108/kg. Engraftment was achieved in all 5 pts with a median of 15(12-18) и 13(10-18) days for granulocytes and platelets, respectively. Skin acute GVHD grade I developed in only 1 pt, and subsided with short course of glucocorticoids. CMV reactivation occurred in 1 pt; there were no episodes of Epstein-Barr Virus (EBV) o rAdenovirus (AdV) reactivation. Full donor myeloid chimerism was established in all pts by day +30. Immune reconstitution was delayed until 6 months after transplant but no severe infections occurred. All pts are alive 1,7-5,5 years (med 4 years) after HSCT with normal hematopoiesis and immune function, full donor chimerism and no late sequelae. CONCLUSION:Transplantation of TCRalfa/beta and CD19 depleted hematopoietic cells from matched unrelated donor after immunoablative conditioning and supported with short course of eculizumab is perfectly safe and efficient technology leading to cure in young patients with PNH. 10.26442/terarkh201890757-64
    Impact of CMV and EBV on Immune Recovery After Allogeneic Hematopoietic Cell Transplantation in Children. Pukownik Ewelina,Kubicka Malgorzata,Kurylo-Rafinska Beata,Debski Robert,Galazka Przemyslaw,Czyzewski Krzysztof,Krenska Anna,Bartoszewicz Natalia,Demidowicz Ewa,Marjańska Agata,Dziedzic Magdalena,Pogorzala Monika,Wysocki Mariusz,Styczynski Jan Anticancer research BACKGROUND/AIM:Immune recovery is a key factor in the management of patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study analyzed the factors contributing to immune reconstitution after allo-HSCT. PATIENTS AND METHODS:Overall, 65 children with malignant or non-malignant diseases were included in multivariate analyses. RESULTS:The following factors contributed to a faster immune recovery: peripheral blood as a stem cell source and reactivation of CMV infection for CD3 and CD4 lymphocyte subpopulations; reactivation of CMV infection for CD8 subset; donor EBV-IgG and no EBV reactivation for CD19 lymphocytes; recipient age below 10 years and peripheral blood as a stem cell source for NK cells. For CD2 and CD4/CD8 ratio no factor was significant in multivariate analysis. CONCLUSION:Patients receiving a graft from an EBV-IgG-positive donor and not having early EBV post-transplant viremia show faster recovery of the B-cells, while patients with early CMV-DNA-emia have a better re-establishment of T-cell subsets. 10.21873/anticanres.12950
    T memory stem cells after allogeneic haematopoietic cell transplantation: unique long-term kinetics and influence of chronic graft-versus-host disease. Jimbo Koji,Konuma Takaaki,Watanabe Eri,Kohara Chisato,Mizukami Motoko,Nagai Etsuko,Oiwa-Monna Maki,Mizusawa Mai,Isobe Masamichi,Kato Seiko,Takahashi Satoshi,Tojo Arinobu British journal of haematology T memory stem cells (TSCMs) are a subset of primitive T cells capable of both self-renewal and differentiation into all subsets of memory and effector T cells. Therefore, TSCMs may play a role in immune reconstitution and graft-versus-host disease (GVHD) in patients receiving allogeneic haematopoietic cell transplantation (HCT). We conducted a cross-sectional study to evaluate the proportions, absolute counts, phenotypes and functions of TSCMs in 152 adult patients without disease recurrence at least 12 months after undergoing HCT. CD4 TSCMs were negatively correlated with number of months after transplantation in HCT patients that received cord blood transplantation, but not in patients that received bone marrow transplantation or peripheral blood stem cell transplantation. The proportions and absolute counts of CD4 TSCMs and expression levels of inducible co-stimulator (ICOS) in CD8 TSCMs were significantly higher in patients with mild and moderate/severe cGVHD compared to patients without cGVHD. These data suggested that, more than 12 months after allogeneic HCT, the kinetics of CD4 TSCMs were dependent on the type of donor source, and further that CD4 TSCMs and ICOS levels in CD8 TSCMs were associated with cGVHD. 10.1111/bjh.15995
    Host and Graft Factors Impacting Infection Risk in Hematopoietic Cell Transplantation. Kao Roy L,Holtan Shernan G Infectious disease clinics of North America Infection contributes significantly to morbidity and mortality in hematopoietic cell transplantation. A complex interplay of host, graft, and technical factors contributes to infectious risk in the recipient. Host factors such as age, underlying disease, and comorbidities; central venous access; and the preparative regimen contribute to mucosal disruption, organ dysfunction, and immunodeficiency before hematopoietic cell transplantation. Graft factors, including donor histocompatibility, cell source, and graft components, along with immunosuppression and graft-versus-host disease, contribute to the speed of immune reconstitution. Evaluation of these factors, plus previous and posttransplant exposure to pathogens, is necessary to best assess an individual recipient's infection risk. 10.1016/j.idc.2019.02.001
    T cell depletion and no post transplant immune suppression allow separation of graft versus leukemia from graft versus host disease. Pierini Antonio,Ruggeri Loredana,Mancusi Antonella,Carotti Alessandra,Falzetti Franca,Terenzi Adelmo,Martelli Massimo Fabrizio,Velardi Andrea Bone marrow transplantation Allogeneic hematopoietic cell transplantation from a human leukocyte antigen (HLA) haplotype mismatched donor (haploidentical transplantation) was not feasible for the treatment of hematologic malignancies until the early 1990s, due to the high risk of rejection and graft-versus-host disease (GVHD). The first successful protocol of haploidentical transplantation was based on a highly myeloablative and immunosuppressive conditioning regimen and the infusion of a "mega-dose" of T-cell-depleted hematopoietic stem cells. More than 90% of patients engrafted and <10% developed GVHD. The protocol did not include post-transplant immunosuppression, which favored the graft-versus-tumor effect mediated by alloreactive NK cells and residual alloreactive T cells. However, donor post-transplant immune reconstitution was slow with a high risk of infection-related mortality. More recently, T-cell-depleted haploidentical transplantation has become the platform for innovative cell therapies that aim to enhance T-cell immunity while preventing adverse reactions against host tissues. One strategy is adoptive immunotherapy with conventional T cells and regulatory T cells. Preclinical studies and clinical trials have proven that regulatory T cells control GVHD caused by co-infused conventional T cells while the graft-versus-tumor effect is retained. The use of regulatory T cells in the absence of any other form of immune suppression allowed for a conventional T cell-mediated full eradication of disease in the vast majority of high-risk acute leukemia patients. 10.1038/s41409-019-0597-y
    Update on current research into haploidentical hematopoietic stem cell transplantation. Sun Yu-Qian,Chang Ying-Jun,Huang Xiao-Jun Expert review of hematology INTRODUCTION:Haploidentical stem cell transplantation (Haplo-SCT) is currently a suitable alternative worldwide for patients with hematological diseases, who lack human leukocyte antigen (HLA)-matched siblings or unrelated donors. Areas covered: This review summarizes the advancements in Haplo-SCT in recent years, primarily focusing on the global trends of haploidentical allograft, the comparison of outcomes between Haplo-SCT and other transplantation modalities, strategies for improving clinical outcomes, including donor selection, hematopoietic reconstitution promotion, and graft-versus-host disease, and relapse prevention/management, as well as the expanded indications of Haplo-SCT, such as severe aplastic anemia, myeloma and lymphoma. Expert commentary: Haploidentical allografts, including granulocyte colony-stimulating factor-based protocol and a post-transplant cyclophosphamide-based protocol, have been the mainstream strategy for Haplo-SCT. However, there are many unanswered questions in this field. 10.1080/17474086.2018.1447379
    TCR αβ+/CD19+ cell depletion in haploidentical hematopoietic allogeneic stem cell transplantation: a review of current data. Sahasrabudhe Kieran,Otto Mario,Hematti Peiman,Kenkre Vaishalee Leukemia & lymphoma Allogeneic hematopoietic stem cell transplantation is a curative option for patients with a variety of diseases. Transplantation from a related haploidentical donor is being increasingly utilized for patients who lack an available human leukocyte antigen matched related or unrelated donor. One of the strategies used for haploidentical transplants involves selective depletion of T cells expressing the αβ T cell receptor and CD19+ B cells prior to transplant. This allows for the removal of cells responsible for graft-versus-host disease and post-transplant lymphoproliferative disorder but maintains hematopoietic progenitor and stem cells for engraftment (CD34+ cells), as well as cells to elicit graft-versus-tumor effect and provide anti-infective activity (such as gamma-delta T cells and natural killer cells). The aim of this review article is to present and discuss the data available to date from studies utilizing this method of transplantation. 10.1080/10428194.2018.1485905
    Immunologic reconstitution following hematopoietic stem cell transplantation despite lymph node paucity in NF-κB-inducing kinase deficiency. Ben Farhat Khaoula,Alosaimi Mohammed F,Shendi Hiba,Al-Hammadi Suleiman,Jones Jennifer,Schwarz Klaus,Schulz Ansgar,Alawdah Laila S,Burchett Sandra,Albuhairi Sultan,Whangbo Jennifer,Kwatra Neha,Shamseldin Hanan E,Alkuraya Fowzan S,Chou Janet,Geha Raif S The Journal of allergy and clinical immunology 10.1016/j.jaci.2018.11.003
    Delay expression of NKp30 on NK cells correlates with long-term mycophenolate mofetil treatment and higher EBV viremia post allogenic hematological stem cells transplantation. Yu Xing-Xing,Cao Xun-Hong,Yan Hong,Luo Xue-Yi,Zhao Xiao-Su,Sun Yu-Qian,Wang Yu,Xu Lan-Ping,Zhang Xiao-Hui,Chang Ying-Jun,Huang Xiao-Jun,Zhao Xiang-Yu Clinical immunology (Orlando, Fla.) Mycophenolate mofetil (MMF) is an immunosuppressive agent that is widely used in graft-versus-host disease prophylaxis because of its inhibitory function on T cells and B cells. However, the effect of MMF on natural killer cell reconstitution after allogenic hematological transplantation is largely unknown. The present study examined the effects of different MMF administration durations after haploidentical allo-HSCT on NK cell reconstitution. Ninety patients were enrolled in this study and defined into two groups in term of MMF duration. We found that MMF patients in the long-term MMF group were associated with a poor reconstitution of NK cells and a significantly lower cytotoxicity from day 30 to day 180 post-transplantation. Especially, the long-term MMF group inhibits reconstitution of NKp30 NK subsets, which correlated with higher risk of EBV viremia. Multivariate analysis showed that a better reconstitution of NKp30 cells was associated with lower EBV viremia (HR0.957, p = .04). In vitro experiments demonstrated that the active metabolite of MMF, mycophenolic acid (MPA), inhibited the proliferation and cytotoxicity of NK cells from healthy donors or patients at day 30 post-transplantation. In summary, our findings demonstrated that long-term MMF administration delayed the quality and quantity of NK cells, especially NKp30 subpopulations, which was associated with decreased EBV viremia post allogeneic HSCT. 10.1016/j.clim.2019.05.010
    Graft Engineering and Adoptive Immunotherapy: New Approaches to Promote Immune Tolerance After Hematopoietic Stem Cell Transplantation. Bertaina Alice,Roncarolo Maria Grazia Frontiers in immunology Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapeutic option for a wide range of immune and hematologic malignant and non-malignant disorders. Once transplanted, allogeneic cells have to support myeloid repopulation and immunological reconstitution, but also need to become tolerant to the host via central or peripheral mechanisms to achieve the desired therapeutic effect. Peripheral tolerance after allogeneic HSCT may be achieved by several mechanisms, though blocking alloreactivity to the host human leukocyte antigens while preserving immune responses to pathogens and tumor antigens remains a challenge. Recently uncovered evidence on the mechanisms of post-HSCT immune reconstitution and tolerance in transplanted patients has allowed for the development of novel cell-based therapeutic approaches. These therapies are aimed at inducing long-term peripheral tolerance and reducing the risk of graft-vs-host disease (GvHD), while sparing the graft-vs-leukemia (GvL) effect. Thus, ensuring effective long term remission in hematologic malignancies. Today, haploidentical stem cell transplants have become a widely used treatment for patients with hematological malignancies. A myriad of and T-cell depletion strategies have been adopted, with the goal of preventing GvHD while preserving GvL in the context of immunogenetic disparity. αβ T-cell/CD19 B-cell depletion techniques, in particular, has gained significant momentum, because of the high rate of leukemia-free survival and the low risk of severe GvHD. Despite progress, better treatments are still needed in a portion of patients to further reduce the incidence of relapse and achieve long-term tolerance. Current post-HSCT cell therapy approaches designed to induce tolerance and minimizing GvHD occurrence include the use of (i) γδ T cells, (ii) regulatory Type 1 T (Tr1) cells, and (iii) engineered FOXP3 regulatory T cells. Future protocols may include post-HSCT infusion of allogeneic effector or regulatory T cells engineered with a chimeric antigen receptor (CAR). In the present review, we describe the most recent advances in graft engineering and post-HSCT adoptive immunotherapy. 10.3389/fimmu.2019.01342
    Innate Immune Responses in the Outcome of Haploidentical Hematopoietic Stem Cell Transplantation to Cure Hematologic Malignancies. Zaghi Elisa,Calvi Michela,Di Vito Clara,Mavilio Domenico Frontiers in immunology In the context of allogeneic transplant platforms, human leukocyte antigen (HLA)-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents one of the latest and most promising curative strategies for patients affected by high-risk hematologic malignancies. Indeed, this platform ensures a suitable stem cell source immediately available for virtually any patents in need. Moreover, the establishment in recipients of a state of immunologic tolerance toward grafted hematopoietic stem cells (HSCs) remarkably improves the clinical outcome of this transplant procedure in terms of overall and disease free survival. However, the HLA-mismatch between donors and recipients has not been yet fully exploited in order to optimize the Graft vs. Leukemia effect. Furthermore, the efficacy of haplo-HSCT is currently hampered by several life-threatening side effects including the onset of Graft vs. Host Disease (GvHD) and the occurrence of opportunistic viral infections. In this context, the quality and the kinetic of the immune cell reconstitution (IR) certainly play a major role and several experimental efforts have been greatly endorsed to better understand and accelerate the post-transplant recovery of a fully competent immune system in haplo-HSCT. In particular, the IR of innate immune system is receiving a growing interest, as it recovers much earlier than T and B cells and it is able to rapidly exert protective effects against both tumor relapses, GvHD and the onset of life-threatening opportunistic infections. Herein, we review our current knowledge in regard to the kinetic and clinical impact of Natural Killer (NK), γδ and Innate lymphoid cells (ILCs) IRs in both allogeneic and haplo-HSCT. The present paper also provides an overview of those new therapeutic strategies currently being implemented to boost the alloreactivity of the above-mentioned innate immune effectors in order to ameliorate the prognosis of patients affected by hematologic malignancies and undergone transplant procedures. 10.3389/fimmu.2019.02794
    Treatment of primary immunodeficiency with allogeneic transplant and gene therapy. Pai Sung-Yun Hematology. American Society of Hematology. Education Program The treatment of primary immunodeficiency disorders with allogeneic hematopoietic cell transplantation (HCT) has a history dating back to 1968 with the first successful transplant for a patient with severe combined immunodeficiency (SCID). The omission of conditioning for patients with SCID owing to their inability to reject allogeneic grafts and the increasing use of reduced intensity conditioning regimens often result in a state of mixed or split donor-recipient chimerism. The use of gene therapy (GT) via retroviral or lentiviral transduction of autologous CD34+ hematopoietic stem and progenitor cells is expected to correct only a portion of the hematopoietic stem cell compartment. The consequences of partial correction after either form of cellular therapy differ according to how the genetic deficiency affects immune cell development and function. Moreover, the conditioning regimen or lack thereof impacts the cell lineages at risk of partial correction. Advances in our understanding of immune reconstitution after HCT and GT for SCID, Wiskott-Aldrich syndrome, and chronic granulomatous disease are discussed. 10.1182/hematology.2019000052
    Insufficient immune reconstitution after allogeneic cord blood transplantation without chemotherapy conditioning in patients with SCID caused by CD3δ deficiency. Takada H,Ishimura M,Hara T Bone marrow transplantation 10.1038/bmt.2016.64
    Autologous reconstitution of human cancer and immune system in vivo. Fu Juan,Sen Rupashree,Masica David L,Karchin Rachel,Pardoll Drew,Walter Vonn,Hayes D Neil,Chung Christine H,Kim Young J Oncotarget Correlative studies from checkpoint inhibitor trials have indicated that better understanding of human leukocytic trafficking into the human tumor microenvironment can expedite the translation of future immune-oncologic agents. In order to directly characterize signaling pathways that can regulate human leukocytic trafficking into the tumor, we have developed a completely autologous xenotransplantation method to reconstitute the human tumor immune microenvironment in vivo. We were able to genetically mark the engrafted CD34+ bone marrow cells as well as the tumor cells, and follow the endogenous leukocytic infiltration into the autologous tumor. To investigate human tumor intrinsic factors that can potentially regulate the immune cells in our system, we silenced STAT3 signaling in the tumor compartment. As expected, STAT3 signaling suppression in the tumor compartment in these autologously reconstituted humanized mice showed increased tumor infiltrating lymphocytes and reduction of arginase-1 in the stroma, which were associated with slower tumor growth rate. We also used this novel system to characterize human myeloid suppressor cells as well as to screen novel agents that can alter endogenous leukocytic infiltration into the tumor. Taken together, we present a valuable method to study individualized human tumor microenvironments in vivo without confounding allogeneic responses. 10.18632/oncotarget.14026
    Long-term leukocyte reconstitution in NSG mice transplanted with human cord blood hematopoietic stem and progenitor cells. Audigé Annette,Rochat Mary-Aude,Li Duo,Ivic Sandra,Fahrny Audrey,Muller Christina K S,Gers-Huber Gustavo,Myburgh Renier,Bredl Simon,Schlaepfer Erika,Scherrer Alexandra U,Kuster Stefan P,Speck Roberto F BMC immunology BACKGROUND:Humanized mice (hu mice) are based on the transplantation of hematopoietic stem and progenitor cells into immunodeficient mice and have become important pre-clinical models for biomedical research. However, data about their hematopoiesis over time are scarce. We therefore characterized leukocyte reconstitution in NSG mice, which were sublethally irradiated and transplanted with human cord blood-derived CD34+ cells at newborn age, longitudinally in peripheral blood and, for more detailed analyses, cross-sectionally in peripheral blood, spleen and bone marrow at different time points. RESULTS:Human cell chimerism and absolute human cell count decreased between week 16 and 24 in the peripheral blood of hu mice, but were stable thereafter as assessed up to 32 weeks. Human cell chimerism in spleen and bone marrow was maintained over time. Notably, human cell chimerism in peripheral blood and spleen as well as bone marrow positively correlated with each other. Percentage of B cells decreased between week 16 and 24, whereas percentage of T cells increased; subsequently, they levelled off with T cells clearly predominating at week 32. Natural killer cells, monocytes and plasmacytoid dendritic cells (DCs) as well as CD1c + and CD141+ myeloid DCs were all present in hu mice. Proliferative responses of splenic T cells to stimulation were preserved over time. Importantly, the percentage of more primitive hematopoietic stem cells (HSCs) in bone marrow was maintained over time. CONCLUSIONS:Overall, leukocyte reconstitution was maintained up to 32 weeks post-transplantation in our hu NSG model, possibly explained by the maintenance of HSCs in the bone marrow. Notably, we observed great variation in multi-lineage hematopoietic reconstitution in hu mice that needs to be taken into account for the experimental design with hu mice. 10.1186/s12865-017-0209-9
    Reconstitution of multifunctional CD56CD16 natural killer cell subset in children with acute leukemia given α/β T cell-depleted HLA-haploidentical haematopoietic stem cell transplantation. Stabile Helena,Nisti Paolo,Peruzzi Giovanna,Fionda Cinzia,Pagliara Daria,Brescia Pomonia Letizia,Merli Pietro,Locatelli Franco,Santoni Angela,Gismondi Angela Oncoimmunology We recently described the CD56CD16 subset of Natural Killer (NK) cells that both mediate cytotoxic activity and produce IFNγ, being more abundant in bone marrow (BM) than in peripheral blood (PB) of pediatric normal subjects. Given the multifunctional properties of this subset, we examined its development and functional recovery in a cohort of children undergoing α/β T-cell depleted HLA-haploidentical haematopoietic stem cell transplantation (HSCT). The results obtained indicate that CD56CD16 NK cells are present in both PB and BM already at one month post-HSCT, with an increased frequency in BM of graft recipients as compared with normal subjects. During the first 6 months after HSCT, no difference in CD56CD16 NK cells distribution between PB and BM was observed. In comparison to normal subjects, CD56CD16 NK cells from transplanted patients show lower expression levels of CD25 and CD127 and higher levels of CD122, and accordingly, produce higher amounts of IFNγ after stimulation with IL-12 plus IL-15. The recovery of NK-cell cytotoxicity after HSCT was strictly restricted to CD56CD16 NK cells, and their ability to degranulate against K562 target cells or autologous leukemic blasts was completely restored only one year after HSCT. Based on the phenotypic and functional ability of reconstituted CD56CD16 NK cells, we suggest that they play an important role in host defense against leukemia relapse and infections after HSCT, and represent an ideal candidate for approaches of adoptive immunotherapy. 10.1080/2162402X.2017.1342024
    In-vivo or ex-vivo T cell depletion or both to prevent graft-versus-host disease after hematopoietic stem cell transplantation. Busca Alessandro,Aversa Franco Expert opinion on biological therapy INTRODUCTION:Hematopoietic stem cell transplantation (HSCT) represents a widely accepted therapeutic strategy for the treatment of hematologic disorders which are otherwise considered incurable. Alloreactive T cells infused with the stem cell inoculum may generate graft-versus-host disease (GVHD) representing one the most relevant obstacles to the successful outcome of patients receiving allogeneic HSCT. Areas covered: In this review, the authors provide an overview of the most recent approaches of T-cell depletion (TCD) including ex-vivo αβ+ TCD and in-vivo TCD with anti-thymocyte globulin (ATG). Expert opinion: Ex vivo depletion of donor T-cells prevents both acute and chronic GVHD without the need for any additional posttransplant immunological prophylaxis either in haploidentical HSCT and HLA matched transplants. Three prospective trials evaluating the efficacy of ATG in matched unrelated donor transplant recipients demonstrated that ATG reduces the incidence of both acute and chronic GVHD without a significant increase of relapse rate, and similar results have been reported in the setting of blood stem cell grafts from matched sibling donors. 10.1080/14712598.2017.1369949
    Treosulfan and Fludarabine Conditioning for Hematopoietic Stem Cell Transplantation in Children with Primary Immunodeficiency: UK Experience. Slatter Mary A,Rao Kanchan,Abd Hamid Intan Juliana,Nademi Zohreh,Chiesa Robert,Elfeky Reem,Pearce Mark S,Amrolia Persis,Worth Austen,Flood Terence,Abinun Mario,Hambleton Sophie,Qasim Waseem,Gaspar Hubert B,Cant Andrew J,Gennery Andrew R,Veys Paul Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation We previously published results for 70 children who received conditioning with treosulfan and cyclophosphamide (n = 30) or fludarabine (n = 40) before undergoing hematopoietic stem cell transplantation (HSCT) for primary immunodeficiency (PID). Toxicity was lower and T cell chimerism was better in the patients receiving fludarabine, but cohort numbers were relatively small and follow-up was short. Here we report outcomes of 160 children who received homogeneous conditioning with treosulfan, fludarabine, and, in most cases, alemtuzumab (n = 124). The median age at transplantation was 1.36 years (range, .09 to 18.25 years). Donors included 73 matched unrelated, 54 1 to 3 antigen-mismatched unrelated, 12 matched sibling, 17 other matched family, and 4 haploidentical donors. Stem cell source was peripheral blood stem cells (PBSCs) in 70, bone marrow in 49, and cord blood in 41. Median duration of follow-up was 4.3 years (range, .8 to 9.4 years). Overall survival was 83%. No patients had veno-occlusive disease. Seventy-four patients (46%) had acute GVHD, but only 14 (9%) greater than grade II. Four patients underwent successful retransplantation for graft loss or poor immune reconstitution. Another patient experienced graft rejection and died. There was no association between T cell chimerism >95% and stem cell source, but a significant association was seen between myeloid chimerism >95% and use of PBSCs without an increased risk of significant GVHD compared with other sources. All 11 patients with severe combined immunodeficiency diagnosed at birth were alive at up to 8.7 years of follow-up. Long-term studies are needed to determine late gonadotoxic effects, and pharmacokinetic studies are needed to identify whether specific targeting is advantageous. The combination of treosulfan, fludarabine, and alemtuzumab is associated with excellent results in HSCT for PID. 10.1016/j.bbmt.2017.11.009
    Distinct Biomarker Profiles in Ex Vivo T Cell Depletion Graft Manipulation Strategies: CD34 Selection versus CD3/19 Depletion in Matched Sibling Allogeneic Peripheral Blood Stem Cell Transplantation. Cantilena Caroline R,Ito Sawa,Tian Xin,Jain Prachi,Chinian Fariba,Anandi Prathima,Keyvanfar Keyvan,Draper Debbie,Koklanaris Eleftheria,Hauffe Sara,Superata Jeanine,Stroncek David,Muranski Pawel,Barrett A John,Battiwalla Minoo Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Various approaches have been developed for ex vivo T cell depletion in allogeneic stem cell transplantation to prevent graft-versus-host disease (GVHD). Direct comparisons of T cell depletion strategies have not been well studied, however. We evaluated cellular and plasma biomarkers in 2 different graft manipulation strategies, CD3CD19 cell depletion (CD3/19D) versus CD34 selection (CD34S), and their associations with clinical outcomes. Identical conditions, including the myeloablative preparative regimen, HLA-identical sibling donor, GVHD prophylaxis, and graft source, were used in the 2 cohorts. Major clinical outcomes were similar in the 2 groups in terms of overall survival, nonrelapse mortality, and cumulative incidence of relapse; however, the cumulative incidence of acute GVHD trended to be higher in the CD3/19D cohort compared with the CD34S cohort. A distinct biomarker profile was noted in the CD3/19D cohort: higher levels of ST2, impaired Helios FoxP3Treg reconstitution, and rapid reconstitution of naïve, Th2, and Th17 CD4 cells in the early post-transplantation period. In vitro graft replication studies confirmed that CD3/19D disproportionately depleted Tregs and other CD4 subset repertoires in the graft. This study confirms the utility of biomarker monitoring, which can be directly correlated with biological consequences and possible future therapeutic indications. 10.1016/j.bbmt.2017.11.028
    Varicella Zoster Virus Reactivation in Adult Survivors of Hematopoietic Cell Transplantation: How Do We Best Protect Our Patients? Lee Catherine J,Savani Bipin N,Ljungman Per Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Reactivation of varicella zoster virus (VZV) remains a significant public health burden for long-term survivors of hematopoietic cell transplantation. Delayed immune reconstitution after transplantation due to immunosuppression, post-transplant therapies, poor engraftment, and graft-versus-host disease leave a large number of patients at risk for herpes zoster (shingles) and its highly morbid complications. Although prophylaxis with acyclovir or valacyclovir has reduced the incidence of VZV reactivation as long as prophylaxis is continued, the incidence of disease in the late post-transplant period or after stopping prophylaxis is greater in the hematopoietic cell transplantation population than the general public. Therefore, additional interventions beyond long-term use of prophylactic antivirals are required to suppress VZV. Vaccines to elicit VZV-specific immunity represent one method to enhance prevention of VZV reactivation, but care must be taken with live vaccines. Inactivated vaccines have been developed and require well-designed studies to determine their safety and efficacy in this high-risk population. Here, we report the available evidence for established and newly developed vaccines for VZV and discuss our view on their role in protecting our transplant survivors against VZV reactivation. 10.1016/j.bbmt.2018.04.003
    Immune Monitoring of Infectious Complications in Transplant Patients: an Important Step towards Improved Clinical Management. Khanna Rajiv Journal of clinical microbiology Immune reconstitution following organ transplantation is absolutely critical in preventing infectious complications. However, understanding the kinetics of immune reconstitution and its potential impact on the clinical management of transplant patients remains a significant challenge. Over the last decade, various platform technologies have emerged which have provided important insights into the immune reconstitution kinetics in transplant patients. However, many of these technologies are too complicated and cumbersome to implement in a clinical setting. In this issue of the , Chiereghin et al. (J. Clin. Microbiol. 56:e01040-17, 2018, https://doi.org/10.1128/JCM.01040-17) report the results of their evaluation of the QuantiFERON-CMV (QFN-CMV) assay to assess human cytomegalovirus (CMV)-specific CD8 T-cell immunity in heart transplant recipients as a prognostic tool. These studies showed that patients with absence of global immune reactivity in the QFN-CMV assay were at a higher risk of developing CMV after discontinuing antiviral prophylaxis. Furthermore, failure to reconstitute CMV-specific immunity after resolution of the first episode of viremia was associated with viral relapse. These observations, along with other recent clinical studies utilizing the QFN-CMV assay, demonstrate that systematic monitoring of antiviral immunity can be successfully used as a prognostic tool and also to guide changes to the clinical management of transplant patients. 10.1128/JCM.02009-17
    Peripheral blood biomarkers of early immune reconstitution in newly diagnosed multiple myeloma. Binder Moritz,Rajkumar S Vincent,Lacy Martha Q,Gertz Morie A,Buadi Francis K,Dispenzieri Angela,Hwa Yi L,Fonder Amie,Hobbs Miriam,Hayman Suzanne R,Zeldenrust Steven R,Lust John A,Russell Stephen J,Leung Nelson,Kapoor Prashant,Go Ronald S,Gonsalves Wilson I,Kourelis Taxiarchis,Warsame Rahma,Kyle Robert A,Kumar Shaji K American journal of hematology Peripheral blood biomarkers of tumor microenvironment and immune surveillance are independent prognostic factors in multiple myeloma. The timing and prognostic impact of immune reconstitution has been studied after autologous hematopoietic stem cell transplantation, less is known about its significance in newly diagnosed multiple myeloma. We studied absolute lymphocyte (ALC) and absolute monocyte (AMC) counts at the time of treatment initiation and 1 month thereafter in 771 newly diagnosed patients. Two hundred and thirty-four patients (31%) had evidence of immune dysregulation at baseline (abnormal biomarkers). Eighty-seven of these patients (37%) recovered normal biomarkers at 1 month (early immune reconstitution). The absence of immune dysregulation at baseline (compared to the presence thereof) was associated with better overall survival (HR 0.77, 95% CI 0.61-0.97, P = 0.025, n = 771). The absence of immune dysregulation at 1 month (compared to the persistence or development thereof) was associated with better overall survival (HR 0.63, 95% CI 0.50-0.80, P < 0.001, n = 771). Early immune reconstitution (compared to the persistence or development of immune dysregulation) was associated with better overall survival (HR 0.62, 95% CI 0.43-0.92, P = 0.016, n = 771). Cytogenetic high-risk disease was negatively, and treatment with immunomodulators positively, associated with early immune reconstitution. The presence or development of immune dysregulation in newly diagnosed multiple myeloma is an independent risk factor. The favorable impact of early immune reconstitution suggests immune dysregulation to be a potentially modifiable risk factor that may be exploited for therapeutic benefit. 10.1002/ajh.25365
    Learning the next-generation sequencing alphabet of immune reconstitution: factors determining CD8 T-cell receptor α-chain repertoire dynamics after hematopoietic stem cell transplantation. Arrieta-Bolaños Esteban,Fleischhauer Katharina Haematologica 10.3324/haematol.2018.209130
    Naive and Stem Cell Memory T Cell Subset Recovery Reveals Opposing Reconstitution Patterns in CD4 and CD8 T Cells in Chronic Graft vs. Host Disease. Soares Maria V,Azevedo Rita I,Ferreira Inês A,Bucar Sara,Ribeiro Ana C,Vieira Ana,Pereira Paulo N G,Ribeiro Ruy M,Ligeiro Dario,Alho Ana C,Soares António S,Camacho Nádia,Martins Carlos,Lourenço Fernanda,Moreno Raul,Ritz Jerome,Lacerda João F Frontiers in immunology The success of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of hematological malignancies remains hampered by life-threatening chronic graft vs. host disease (cGVHD). Although multifactorial in nature, cGVHD has been associated with imbalances between effector and regulatory T cells (Treg). To further elucidate this issue, we performed a prospective analysis of patients undergoing unrelated donor allo-HSCT after a reduced intensity conditioning (RIC) regimen containing anti-thymocyte globulin (ATG) and the same GVHD prophylaxis, at a single institution. We studied T cell subset homeostasis over a 24-month follow-up after HSCT in a comparative analysis of patients with and without cGVHD. We also quantified naive and memory T cell subsets, proliferation and expression of the apoptosis-related proteins Bcl-2 and CD95. Finally, we assessed thymic function by T cell receptor excision circle (TREC) quantification and T cell receptor (TCR) diversity by TCRVβ spectratyping. While the total number of conventional CD4 (Tcon) and CD8 T cells was similar between patient groups, Treg were decreased in cGVHD patients. Interestingly, we also observed divergent patterns of Naive and Stem Cell Memory (SCM) subset recovery in Treg and Tcon compared to CD8. Patients with cGVHD showed impaired recovery of Naive and SCM Tcon and Treg, but significantly increased frequencies and absolute numbers of Naive and SCM were observed in the CD8 pool. Markedly increased EMRA CD8 T cells were also noted in cGVHD. Taken together, these results suggest that Naive, SCM and EMRA CD8 play a role in the emergence of cGHVD. Reduced Naive and recent thymic emigrant Tcon and Treg in cGVHD was likely due to impaired thymic output, as it was accompanied by decreased CD4 TREC and TCR diversity. On the other hand, CD8 TCR diversity was similar between patient groups. Furthermore, no correlation was observed between CD8 TREC content and Naive CD8 numbers, suggesting limited thymic production of Naive CD8 T cells in patients after transplant, especially in those developing cGVHD. The mechanisms behind the opposing patterns of CD4 and CD8 subset cell recovery in cGVHD remain elusive, but may be linked to thymic damage associated with the conditioning regimen and/or acute GVHD. 10.3389/fimmu.2019.00334
    Impact of alemtuzumab pharmacokinetics on T-cell dynamics, graft-versus-host disease and viral reactivation in patients receiving allogeneic stem cell transplantation with an alemtuzumab-based T-cell-depleted graft. Loeff Floris C,van Egmond Esther H M,Moes Dirk J A R,Wijnands Charissa,Von Dem Borne Peter A,Veelken Hendrik,Falkenburg J H Frederik,Jedema Inge,Halkes Constantijn J M Transplant immunology Administration of alemtuzumab (targeting the CD52 antigen) to the patient (in-vivo) or to the graft (in-vitro) before allogeneic stem cell transplantation (alloSCT) decreases the incidence of graft-versus-host disease (GvHD). Effectiveness of this treatment relies on depletion of donor T cells. Currently, no data are available on alemtuzumab pharmacokinetics and pharmacodynamics in patients who received combined in-vivo and in-vitro alemtuzumab-based T-cell depletion. In this prospective study, we analyzed alemtuzumab pharmacokinetics and its effect on the circulating T cells in 36 patients who received an allogeneic T-cell-depleted graft by addition of 20 mg alemtuzumab "to the bag" with or without prior alemtuzumab (30 mg cumulative dose intravenously) as part of the conditioning regimen. Effective T-cell depletion was shown for all patients, even though alemtuzumab plasma levels varied considerably. Peak alemtuzumab levels were observed directly after graft infusion and were not associated with the number of circulating T cells pre-infusion, but with plasma volumes of the patients. All patients engrafted, confirming feasibility of this transplantation protocol. Only three patients with low alemtuzumab levels developed acute GvHD (grade II in 2 patients and grade III in 1 patient). Persistence of circulating alemtuzumab at 3 weeks after transplantation had prevented reconstitution of CD52-positive T cells when alemtuzumab plasma levels were above 0.7 μg/mL. However, overall T-cell reconstitution did not correlate with the levels of alemtuzumab exposure, due to early reconstitution of CD52-negative alemtuzumab-resistant T cells. The protective effect of these cells likely explains the low incidence of Epstein-Barr-virus- and cytomegalovirus-related disease despite circulating alemtuzumab. 10.1016/j.trim.2019.06.001
    Mutual Interference between Cytomegalovirus and Reconstitution of Protective Immunity after Hematopoietic Cell Transplantation. Reddehase Matthias J Frontiers in immunology Hematopoietic cell transplantation (HCT) is a therapy option for aggressive forms of hematopoietic malignancies that are resistant to standard antitumoral therapies. Hematoablative treatment preceding HCT, however, opens a "window of opportunity" for latent Cytomegalovirus (CMV) by releasing it from immune control with the consequence of reactivation of productive viral gene expression and recurrence of infectious virus. A "window of opportunity" for the virus represents a "window of risk" for the patient. In the interim between HCT and reconstitution of antiviral immunity, primarily mediated by CD8(+) T cells, initially low amounts of reactivated virus can expand exponentially, disseminate to essentially all organs, and cause multiple organ CMV disease, with interstitial pneumonia (CMV-IP) representing the most severe clinical manifestation. Here, I will review predictions originally made in the mouse model of experimental HCT and murine CMV infection, some of which have already paved the way to translational preclinical research and promising clinical trials of a preemptive cytoimmunotherapy of human CMV disease. Specifically, the mouse model has been pivotal in providing "proof of concept" for preventing CMV disease after HCT by adoptive transfer of preselected, virus epitope-specific effector and memory CD8(+) T cells bridging the critical interim. However, CMV is not a "passive antigen" but is a pathogen that actively interferes with the reconstitution of protective immunity by infecting bone marrow (BM) stromal cells that otherwise form niches for hematopoiesis by providing the structural microenvironment and by producing hematopoietically active cytokines, the hemopoietins. Depending on the precise conditions of HCT, reduced homing of transplanted hematopoietic stem- and progenitor cells to infected BM stroma and impaired colony growth and lineage differentiation can lead to "graft failure." In consequence, uncontrolled virus spread causes morbidity and mortality. In the race between viral BM pathology and reconstitution of antiviral immunity following HCT, exogenous reconstitution of virus-specific CD8(+) T cells by adoptive cell transfer as an interventional strategy can turn the balance toward control of CMV. 10.3389/fimmu.2016.00294
    Relation between Acute GVHD and NK Cell Subset Reconstitution Following Allogeneic Stem Cell Transplantation. Ullrich Evelyn,Salzmann-Manrique Emilia,Bakhtiar Shahrzad,Bremm Melanie,Gerstner Stephanie,Herrmann Eva,Bader Peter,Hoffmann Petra,Holler Ernst,Edinger Matthias,Wolff Daniel Frontiers in immunology One of the major challenges of allogeneic stem cell transplantation (allo-SCT) is to reduce the risk of graft-versus-host disease (GVHD) while boosting the graft-versus-leukemia (GVL) effect. The reconstitution of natural killer (NK) cells following allo-SCT is of notable interest due to their known capability to induce GVL without GVHD. Here, in this study, we investigate the association between the incidence and severity of acute graft-versus-host disease (aGVHD) and the early reconstitution of NK cell subsets following allo-SCT. We analyzed 342 samples from 107 patients using flow cytometry, with a focus on immature CD56 and mature cytotoxic CD56 NK cells. Longitudinal analysis of immune reconstitution after allo-SCT showed that the incidence of aGVHD was associated with a delayed expansion of the entire NK cell population, in particular the CD56 subset. Notably, the disturbed reconstitution of the CD56 NK cells also correlated with the severity of aGVHD. 10.3389/fimmu.2016.00595
    Early recovery of T-cell function predicts improved survival after T-cell depleted allogeneic transplant. Goldberg Jenna D,Zheng Junting,Ratan Ravin,Small Trudy N,Lai Kuan-Chi,Boulad Farid,Castro-Malaspina Hugo,Giralt Sergio A,Jakubowski Ann A,Kernan Nancy A,O'Reilly Richard J,Papadopoulos Esperanza B,Young James W,van den Brink Marcel R M,Heller Glenn,Perales Miguel-Angel Leukemia & lymphoma Infection, relapse, and GVHD can complicate allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although the effect of poor immune recovery on infection risk is well-established, there are limited data on the effect of immune reconstitution on relapse and survival, especially following T-cell depletion (TCD). To characterize the pattern of immune reconstitution in the first year after transplant and its effects on survival and relapse, we performed a retrospective study in 375 recipients of a myeloablative TCD allo-HSCT for hematologic malignancies. We noted that different subsets recover sequentially, CD8 + T cells first, followed by total CD4 + and naïve CD4 + T cells, indicating thymic recovery during the first year after HSCT. In the multivariate model, a fully HLA-matched donor and recovery of T-cell function, assessed by PHA response at 6 months, were the only factors independently associated with OS and EFS. In conclusion, T-cell recovery is an important predictor of outcome after TCD allo-HSCT. 10.1080/10428194.2016.1265113
    Low-dose post-transplant cyclophosphamide can mitigate GVHD and enhance the G-CSF/ATG induced GVHD protective activity and improve haploidentical transplant outcomes. Wang Yu,Chang Ying-Jun,Chen Lu,Xu Lan-Ping,Bian Zhi-Lei,Zhang Xiao-Hui,Yan Chen-Hua,Liu Kai-Yan,Huang Xiao-Jun Oncoimmunology Use of high-dose, post-transplant cyclophosphamide (PTCy) results in low rates of graft-versus-host-disease (GVHD) and favorable immune reconstitution, although with higher rates of relapse and somewhat high rates of graft failure. We hypothesized that permissible dose reduction of PTCy might be feasible. The current study attempts to establish a murine model and focus on regulatory T cells (Tregs) to clarify the immunological mechanisms for GVHD prevention by low-dose PTCy. In addition, a prospective, clinical cohort study in haploidentical, T-cell replete transplantation is initiated to support the rational. We found that acute GVHD could be alleviated by low-dose PTCy and could be further mitigated after the combined use of low-dose PTCy and antithymocyte globulin (ATG) in mice. Flow-cytometric analyses in mice showed that low-dose PTCy could increase the number of Tregs and the effect on Tregs is significantly prominent with the combined use of low-dose PTCy and ATG. In the clinical cohort study, the cumulative incidence of grades II-IV acute GVHD in combined treatment cohort with low-dose PTCy and ATG/granulocyte colony-stimulating factor (G-CSF) (17%; 95% CI, 5-29%) was significantly lower than both that in matched-pair cohort (33%; 95% CI, 25-41%; P = 0.04) and that in historical cohort (56%; 95% CI, 42-70%; P < 0.001). In-vivo immune reconstitution analysis showed that low-dose PTCy could facilitate suppressive Tregs reconstitution. In conclusion, low-dose PTCy is sufficient for GVHD abrogation under lymphopenic situation and can enhance the protective effect of ATG/G-CSF on GVHD. Intensified conditioning followed by low-dose PTCy might be a feasible option for patients undergoing haploidentical transplantation. 10.1080/2162402X.2017.1356152
    Dynamics of B Cell Recovery In Kidney/Bone Marrow Transplant Recipients. Gao Baoshan,Gu Yiming,Rong Chunshu,Moore Carolina,Porcheray Fabrice,Wong Waichi,Preffer Frederic,Saidman Susan L,Fu Yaowen,Cosimi Benedict,Sachs David H,Kawai Tatsuo,Sykes Megan,Zorn Emmanuel Transplantation BACKGROUND:Previous studies identified B cell gene signatures and predominance of specific B cell subsets as a marker of operational tolerance after kidney transplantation. These findings suggested a role for B cells in the establishment or maintenance of tolerance. Here we analyzed B cell recovery in 4 subjects, 3 of whom achieved tolerance after combined kidney/bone marrow transplantation. METHODS:Peripheral B cell subsets were examined longitudinally by flow cytometry. Immunoglobulin heavy chain repertoire analysis was performed using next-generation sequencing. Lastly, the patients' serum reactivity to HLA was assessed by Luminex. RESULTS:B cell counts recovered approximately 1 year posttransplant except for 1 subject who experienced delayed reconstitution. This subject resumed immunosuppression for acute rejection at 10 months posttransplant and underwent preemptive retransplantation at 3 years for chronic rejection. B cell recovery was accompanied by a high frequency of CD20 + CD24CD38 transitional B cells and a diversified clonal repertoire. However, all 4 subjects showed prevalence of CD20 + CD27+ memory B cells around 6 months posttransplant when B cell counts were still low and the clonal B cell repertoire very limited. The predominance of memory B cells was also associated with high levels of somatically mutated immunoglobulin heavy chain variable sequences and transient serum reactivity to HLA. CONCLUSIONS:Our observations reveal the presence of memory B cells early posttransplant that likely escaped the preparative regimen at a time consistent with the establishment of tolerance. Further studies are warranted to characterize the functional properties of these persisting memory cells and evaluate their potential contribution to tolerance induction. 10.1097/TP.0000000000001789
    Inverse correlation of Vδ2 T-cell recovery with EBV reactivation after haematopoietic stem cell transplantation. Liu Jiangying,Bian Zhilei,Wang Xiaoyu,Xu Lan-Ping,Fu Qiang,Wang Chenguang,Chang Ying-Jun,Wang Yu,Zhang Xiao-Hui,Jiang Zhengfan,Huang Xiao-Jun British journal of haematology Epstein-Barr virus (EBV) reactivation remains a life-threatening complication in recipients of a haploidentical haematopoietic stem cell transplantation (haploHSCT). Reconstitution of adaptive T lymphocytes is generally compromised at the early stages following transplant, suggesting an important role of other effector cells in preventing EBV infection. Our previous studies demonstrated that recovery of CD4 CD8 T cells negatively correlated with EBV reactivation after haploHSCT. In this prospective study on 132 adult patients with haematopoietic malignancy, recovery of T-cell subpopulations was characterized post-haploHSCT. We showed that the median counts of peripheral Vδ2 cells were continuously lower in recipients with EBV reactivation compared with controls at 30, 60 and 90 days after haploHSCT (P values: 0·006, <0·001 and 0·019, respectively). Landmark study further indicated that the cumulative incidence of EBV reactivation was significantly decreased in recipients with higher day-30 Vδ2 counts. Activation of Vδ2 cells upon EBV reactivation was accompanied by an induction of cell apoptosis. Cytotoxic effect of Vδ2 cells on EBV-infected cells was confirmed by in vitro experiments. Together, our findings uncovered a significant correlation of recovered Vδ2 with EBV reactivation following haploHSCT. These results will help to better understand the intrinsic anti-virus immunity and develop γδ T-based therapy strategies after haematopoietic transplantation. 10.1111/bjh.15037
    Management of post-transplant lymphoproliferative disorders. DeStefano Christin B,Desai Sanjal H,Shenoy Aarthi G,Catlett Joseph P British journal of haematology The post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of neoplasms that are one of the most serious complications of bone marrow and solid organ transplants. Because these disorders are rare, there are no randomized trials from which to derive optimal treatment. Management can be challenging and must balance the goal of PTLD eradication with the risks of graft rejection, graft-versus-host disease, further delays in immune reconstitution and life-threatening infections, among others. This paper will provide a comprehensive review of PTLD following solid organ transplant and haematopoietic stem cell transplant with a focus on management. Included is a discussion of novel agents that are being studied in clinical trials and, when combined or sequenced with conventional therapy, have the potential to improve outcomes. 10.1111/bjh.15263
    Quantity and Quality Reconstitution of NKG2A Natural Killer Cells Are Associated with Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation. Hu Li-Juan,Zhao Xiang-Yu,Yu Xing-Xing,Lv Meng,Han Ting-Ting,Han Wei,Huang Xiao-Jun Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation The immune mechanism underlying graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (HSCT) remains unclear. Natural killer (NK) cells play a crucial role in mediating pathogen-specific immunity and are the first donor-derived lymphocytes reconstituted post-HSCT. However, NK cells vary at different stages after HSCT. Here, we found that the absolute NKG2A subset cell counts and the percentages of NKG2A among NK cells were significantly reduced in GVHD patients after HSCT compared with those from non-GVHD patients. Moreover, the reduction in NKG2A NK cells in post-HSCT GVHD patients was ascribed to increased apoptosis and a decreased proliferation capacity while retaining a strong graft-versus-leukemia effect. In vitro assays showed that co-culture of T cells with NKG2A NK cells significantly reduced IFN-γ secretion by T cells and increased IL-4 secretion. Moreover, the CD25 expression level was decreased, whereas the number of cells with the CD4CD25FOXP3 phenotype was increased. In addition, the NKG2A NK cells induced T cell apoptosis and decreased T cell proliferation during the co-culture process. Importantly, NKG2A NK cells mainly regulated activated but not resting T cells. In vivo assays showed that the serologic IL-10 level was evidently lower in GVHD than in non-GVHD patients, whereas the IL-1β, IFN-γ, and tumor necrosis factor-α levels were higher in GVHD patients. Furthermore, the NKG2A NK cell ratio from GVHD patients was markedly increased by the presence of exogenous IL-10 but not by other cytokines. In contrast, the NKG2A cell ratio from non-GVHD patients was not increased by IL-10. Therefore, post-HSCT GVHD may be ascribed to the reduced induction of NKG2A NK cells by IL-10, which further overactivates T cells. 10.1016/j.bbmt.2018.08.008
    Haploidentical Stem Cell Transplantation in Children With Hematological Malignancies Using αβ T-Cell Receptor and CD19 Cell Depleted Grafts: High CD56/CD56 NK Cell Ratio Early Following Transplantation Is Associated With Lower Relapse Incidence and Better Outcome. Diaz Miguel A,Zubicaray Josune,Molina Blanca,Abad Lorea,Castillo Ana,Sebastian Elena,Galvez Eva,Ruiz Julia,Vicario Jose Luis,Ramirez Manuel,Sevilla Julian,González-Vicent Marta Frontiers in immunology We prospectively analyzed outcomes of haploidentical hematopoietic stem cell transplantation using αβ T-cell receptor/CD19 depleted grafts. Sixty-three transplantations were performed in 60 patients. Twenty-eight patients were diagnosed with acute lymphoblastic leukemia (ALL), 27 patients were diagnosed with acute myelogenous leukemia, and in eight other hematological malignancies were diagnosed. Twenty-three were in first complete remission (CR), 20 in second CR, 20 beyond second CR. Four patients developed graft failure. Median time to neutrophil and platelet recovery was 14 (range 9-25) and 10 days (range 7-30), respectively. The probability of non-relapse mortality (NRM) by day +100 after transplantation was 10 ± 4%. With a median follow-up of 28 months, the probability of relapse was 32 ± 6% and disease-free survival was 52 ± 6%. Immune reconstitution was leaded by NK cells. As such, a high CD56CD56 NK cell ratio early after transplantation was associated with better disease-free survival (DFS) (≥3.5; 77 ± 8% vs. <3.5; 28 ± 5%; = 0.001) due to lower relapse incidence (≥3.5; 15 ± 7% vs. <3.5; 37 ± 9%; = 0.04). T-cell reconstitution was delayed and associated with severe infections after transplant. Viral reactivation/disease and presence of venooclusive disease of liver in the non-caucasian population had a significant impact on NRM. αβ T-cell receptor/CD19 cell-depleted haploidentical transplant is associated with good outcomes especially in patients in early phase of disease. A rapid expansion of "mature" natural killer cells early after transplantation resulted on lower probability of relapse, suggesting a graft vs. leukemia effect independent from graft-vs.-host reactions. 10.3389/fimmu.2019.02504
    NK Cell Reconstitution in Paediatric Leukemic Patients after T-Cell-Depleted HLA-Haploidentical Haematopoietic Stem Cell Transplantation Followed by the Reinfusion of iCasp9-Modified Donor T Cells. Stabile Helena,Nisti Paolo,Fionda Cinzia,Pagliara Daria,Gaspari Stefania,Locatelli Franco,Santoni Angela,Gismondi Angela Journal of clinical medicine T-cell-depleted (TCD) human leukocyte antigen (HLA) haploidentical (haplo) hematopoietic stem cell transplantation (HSCT) (TCD-haplo-HSCT) has had a huge impact on the treatment of many haematological diseases. The adoptive transfer of a titrated number of T cells genetically modified with a gene suicide can improve immune reconstitution and represents an interesting strategy to enhance the success of haplo-HSCT. Natural killer (NK) cells are the first donor-derived lymphocyte population to reconstitute following transplantation, and play a pivotal role in mediating graft-versus-leukaemia (GvL). We recently described a CD56CD16 NK cell subset that mediates both cytotoxic activity and cytokine production. Given the multifunctional properties of this subset, we studied its functional recovery in a cohort of children given α/βT-cell-depleted haplo-HSCT followed by the infusion of a titrated number of iCasp-9-modified T cells (iCasp-9 HSCT). The data obtained indicate that multifunctional CD56CD16 NK cell frequency is similar to that of healthy donors (HD) at all time points analysed, showing enrichment in the bone marrow (BM). Interestingly, with regard to functional acquisition, we identified two groups of patients, namely those whose NK cells did (responder) or did not (non responder) degranulate or produce cytokines. Moreover, in patients analysed for both functions, we observed that the acquisition of degranulation capacity was not associated with the ability to produce interferon-gamma (IFN-γ Intriguingly, we found a higher BM and peripheral blood (PB) frequency of iCas9 donor T cells only in patients characterized by the ability of CD56CD16 NK cells to degranulate. Collectively, these findings suggest that donor iCasp9-T lymphocytes do not have a significant influence on NK cell reconstitution, even if they may positively affect the acquisition of target-induced degranulation of CD56CD16 NK cells in the T-cell-depleted haplo-HSC transplanted patients. 10.3390/jcm8111904
    [Comparison of immune reconstitution at early stage after unmanipulated haploidentical stem cell transplantation between high- and standard- risk Philadelphia chromosome- negative acute lymphoblastic leukemia patients in CR1]. Bian Z L,Chang Y J,Xu L P,Wang Y,Zhang X H,Liu K Y,Huang X J Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi OBJECTIVE:To compare the early stage immune reconstitution of high- and standard-risk Philadelphia chromosome- negative acute lymphoblastic leukemia (ALL) CR1 patients who had haploidentical blood and marrow stem cell transplantation (HBMT). METHODS:A total of 49 Ph-negative ALL CR1 patients who received HBMT and had complete early stage immune reconstitution data(+30, +60 and +90 d post transplantation) from Jan. 2010 to Dec. 2012 were enrolled. Immunophenotyping for B and T lymphocytes was performed post HBMT via flow cytometry. Fresh peripheral blood cells were stained with fluorochrome-labeled monoclonal antibodies against cluster of differentiation CD19, CD3, CD4, CD8, CD45RO, CD45RA and CD28. The early reconstitution of lymphocyte subsets, survival and prognosis between standard- risk group, high- risk adult group and high- risk children group were compared. RESULTS:There were no significant differences in all these T lymphocyte subsets among three groups at the three check points (P>0.05). Moreover, at the same time, comparable outcome had been achieved between standard-risk group (n=18), high-risk adult group (n=16) and high-risk children group (n=15). There were no differences in 2- y relapse incidence (27.8% vs 31.3% vs 26.7%, P=0.957), 2- y non- relapse mortality (11.1% vs 0 vs 13.3%, P=0.185), 2- y leukemia free survival (61.1% vs 68.8% vs 60.0%, P=0.834) and overall survival (77.8% vs 68.8% vs 60.0%, P=0.529) among the three groups. Incidence of grade Ⅱ-Ⅳ aGVHD was 44.4% vs 12.5% vs 46.7% (P=0.075) and incidence of cGVHD was 61.1% vs 50.0% vs 40.0% (P=0.249). CONCLUSION:Comparison of immune reconstitution at early stage may be a reasonable cause to explain that equivalent outcomes were observed among high- and standard- risk Ph- negative ALL CR1 patients after HBMT. 10.3760/cma.j.issn.0253-2727.2016.08.004
    [Early immune reconstitution after hematopoietic stem cell transplantation]. Zhu M X,Wan W L,Li H S,Wang J,Wang Y F,Hu K,Ke X Y Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences OBJECTIVE:To search for differences in early immune reconstitution after allogenic or autologous hematopoietic stem cell transplantation (HSCT). METHODS:The peripheral blood (PB) from 31 adult patients undergoing allogenic HSCT (allo-HSCT, 15 patients) or autologous HSCT (auto-HSCT, 16 patients) for the treatment of hematological malignancies and from 20 related healthy controls (HC) from December 2011 to August 2014 was used to analyze the kinetic recovery of lymphocyte subsets by means of flow cytometry during 12 months after HSCT. The T cell receptor rearrangement excision circle (TREC) levels among CD3(+) T cells were measured in the patients and HC to evaluate the thymic-dependent T cell reconstitution. RESULTS:The allo- and auto-HSCT recipients did not differ significantly in CD4(+) T cells, CD8 naive T cells, effecter memory T cells (TEM), CD4 central memory T cells (TCM), mid-activated T cells and dendritic cells (DC)during the follow-up (P>0.05). But they both differed significantly from HC (P<0.05). CD8(+) T cells and NK cells reconstructed rapidly. There was no significant difference in the numbers of B cells between the allo- and auto-HSCT groups from M1 to M3 (P>0.05). B cells in both the groups were lower than those in HC (P<0.05). The recovery of B cells in auto-HSCT group was faster than in allo-HSCT group at M6 and M12 (P<0.05). The frequencies of CD4 naive T cells and later activated T cells in allo-HSCT group were significantly higher than in auto-HSCT group at M6 and M12 (P<0.05). The frequencies of CD8 TCM in auto-HSCT group were significantly higher than in allo-HSCT group at M6 and M12 (P<0.05). The TREC levels were significantly lower than in both the groups compared with the age-matched HC during the follow-up (P<0.05). No significant difference was observed between allo-HSCT and auto-HSCT groups (P>0.05). CONCLUSION:The differences of the nature and the speed of lymphocyte reconstitution observed between the two patents groups were minor. This leads us to conclude that in allografted patients, immune reconstitution and subpopulations of peripheral blood lymphocytes are probably not related to the allogenicity of the graft, but due to the impaired thymus functions and slow differentiation of T lymphocytes in thymus.
    CMV-specific immune reconstitution following allogeneic stem cell transplantation. Blyth Emily,Withers Barbara,Clancy Leighton,Gottlieb David Virulence Cytomegalovirus (CMV) remains a major contributor to morbidity and mortality following allogeneic haemopoietic stem cell transplant (HSCT) despite widespread use of viraemia monitoring and pre-emptive antiviral therapy. Uncontrolled viral replication occurs primarily in the first 100 d post transplant but this high risk period can extend to many months if immune recovery is delayed. The re-establishment of a functional population of cellular effectors is essential for control of virus replication and depends on recipient and donor serostatus, the stem cell source, degree of HLA matching and post-transplant factors such as CMV antigen exposure, presence of GVHD and ongoing use of immune suppression. A number of immune monitoring assays exist but have not yet become widely accessible for routine clinical use. Vaccination, adoptive transfer of CMV specific T cells and a number of graft engineering processes are being evaluated to enhance of CMV specific immune recovery post HSCT. 10.1080/21505594.2016.1221022
    High Mutation Frequency of the Gene in T Cells Results in Reconstitution of GPI Anchor/CD52 T Cells That Can Give Early Immune Protection after Alemtuzumab-Based T Cell-Depleted Allogeneic Stem Cell Transplantation. Loeff Floris C,Falkenburg J H Frederik,Hageman Lois,Huisman Wesley,Veld Sabrina A J,van Egmond H M Esther,van de Meent Marian,von dem Borne Peter A,Veelken Hendrik,Halkes Constantijn J M,Jedema Inge Journal of immunology (Baltimore, Md. : 1950) Alemtuzumab (ALM) is used for T cell depletion in the context of allogeneic hematopoietic stem cell transplantation (alloSCT) to prevent acute graft-versus-host disease and graft rejection. Following ALM-based T cell-depleted alloSCT, relatively rapid recovery of circulating T cells has been described, including T cells that lack membrane expression of the GPI-anchored ALM target Ag CD52. We show, in a cohort of 89 human recipients of an ALM-based T cell-depleted alloSCT graft, that early lymphocyte reconstitution always coincided with the presence of large populations of T cells lacking CD52 membrane expression. In contrast, loss of CD52 expression was not overt within B cells or NK cells. We show that loss of CD52 expression from the T cell membrane resulted from loss of GPI anchor expression caused by a highly polyclonal mutational landscape in the gene. This polyclonal mutational landscape in the gene was also found in CD52 T cells present at a low frequency in peripheral blood of healthy donors. Finally, we demonstrate that the GPI/CD52 T cell populations that arise after ALM-based T cell-depleted alloSCT contain functional T cells directed against multiple viral targets that can play an important role in immune protection early after ALM-based T cell-depleted transplantation. 10.4049/jimmunol.1701018
    Allogeneic hematopoietic stem-cell transplantation from haploidentical donors using 'ex-vivo' T-cell depletion in pediatric patients with hematological malignancies: state of the art review. González-Vicent Marta,Díaz Perez Miguel A Current opinion in oncology PURPOSE OF REVIEW:Nowadays, T-cell-depleted haploidentical transplantation is considered a valid approach for children lacking a human leukocyte antigen (HLA) identical donor for allogeneic transplantation. This kind of allogeneic transplant is now widely used especially for pediatric patients with high-risk hematological malignancies. However, relapsing disease and life-threatening viral infections are still relevant clinical problems as a consequence of delayed immune reconstitution. Adoptive cell therapies have been proposed to overcome this problem. RECENT FINDINGS:After initial clinical approach using CD34+ selection as method for T-cell depletion (TCD), it was observed that immune reconstitution was delayed and it resulted on high incidence of opportunistic infections and nonrelapse mortality. It is now evident that development over time of graft manipulation techniques for TCD, have provide clinicians a useful tool for overcoming transplant complication such as graft failure, severe graft-vs.-host disease and opportunistic infections. As such, several procedures of almost total or partial TCD have been developed including CD3/CD19 depletion, T cell receptor αβ/CD19 depletion and more recently CD45RA+ depletion. Recent studies showed that immune reconstitution is associated with transplant outcomes. Based on this, haploidentical transplantation is now been explored as platform for cellular therapy to prevent disease recurrence or to treat clinical complications. SUMMARY:Allogeneic transplantation still remains a standard of care for pediatric patients with high-risk hematological malignancies. In absence of an HLA identical donor, T-cell-depleted haploidentical transplant is now considered a valid option and provide a platform for cellular therapy to prevent relapse disease or to treat opportunistic infections. 10.1097/CCO.0000000000000480
    The Evolution of T Cell Depleted Haploidentical Transplantation. Aversa Franco,Pierini Antonio,Ruggeri Loredana,Martelli Massimo Fabrizio,Velardi Andrea Frontiers in immunology Work on bone marrow transplantation from haploidentical donor has been proceeding for over 20 years all over the world and new transplant procedures have been developed. To control both graft rejection and graft vs. host disease, some centers have preferred to enhance the intensity of the conditioning regimens and the post-transplant immune suppression in the absence of graft manipulation; others have concentrated on manipulating the graft in the absence of any additional post-transplant immune suppressive agent. Due to the current high engraftment rates, the low incidence of graft-vs.-host disease and regimen related mortality, transplantation from haploidentical donors have been progressively offered even to elderly patients. Overall, survivals compare favorably with reports on transplants from unrelated donors. Further improvements will come with successful implementation of strategies to enhance post-transplant immune reconstitution and to prevent leukemia relapse. 10.3389/fimmu.2019.02769
    Reconstitution of HIV-1 reservoir following high-dose chemotherapy/autologous stem cell transplantation for lymphoma. Delagreverie Héloïse M,Gerard Laurence,Chaillon Antoine,Roelens Marie,Djerroudi Lounes,Salmona Maud,Larghero Jérôme,Galicier Lionel,Simon François,Oksenhendler Eric,Moins-Teisserenc Hélène,Delaugerre Constance AIDS (London, England) OBJECTIVES:Autologous stem cell transplantation following high-dose chemotherapy (HDC/ASCT) is the prime model to study the impact of HDC in HIV-1-infected participants. We analyzed the impact of HDC/ASCT on the resurgent reservoir composition and origin. DESIGN:We included retrospectively a homogenous group of HIV-1-infected patients treated for high-risk lymphoma in a reference center with similar chemotherapy regimens. METHODS:Thirteen participants treated with HDC/ASCT from 2012 to 2015 were included. A median seven longitudinal blood samples per participant were available. Total HIV-1 DNA levels in peripheral blood mononuclear cells (PBMCs) were quantified by quantitative PCR. In six participants with sustained viral suppression, the highly variable C2V3 viral region was subjected to next-generation sequencing. Maximum-likelihood phylogeny trees were generated from the reconstructed viral haplotypes. Lymphocyte subsets were studied by flow cytometry. RESULTS:PBMC-associated HIV-1 DNA levels were stable over time. Viral diversity decreased along lymphoma treatment, but increased promptly back to prechemotherapy numbers after HDC/ASCT. Blood viral populations from all time-points were intermingled in phylogeny trees: the resurgent reservoir was similar to pre-HDC circulating proviruses. Memory subsets were the main contributor to the early restoration of the CD4+ T-cell pool, with a delayed increase in naïve cell counts. CONCLUSIONS:The characterization of HIV-1 reservoir in blood revealed a fast and consistent replenishment from memory CD4+ T cells after HDC/ASCT. As HDC/ASCT is increasingly involved in HIV cure trials with gene-modified hematopoietic stem cells, the management of infected T cells in HIV-positive autologous transplants will be critical. 10.1097/QAD.0000000000002051
    Antibody Conditioning Enables MHC-Mismatched Hematopoietic Stem Cell Transplants and Organ Graft Tolerance. George Benson M,Kao Kevin S,Kwon Hye-Sook,Velasco Brenda J,Poyser Jessica,Chen Angela,Le Alan C,Chhabra Akanksha,Burnett Cassandra E,Cajuste Devon,Hoover Malachia,Loh Kyle M,Shizuru Judith A,Weissman Irving L Cell stem cell Hematopoietic cell transplantation can correct hematological and immunological disorders by replacing a diseased blood system with a healthy one, but this currently requires depleting a patient's existing hematopoietic system with toxic and non-specific chemotherapy, radiation, or both. Here we report an antibody-based conditioning protocol with reduced toxicity and enhanced specificity for robust hematopoietic stem cell (HSC) transplantation and engraftment in recipient mice. Host pre-treatment with six monoclonal antibodies targeting CD47, T cells, NK cells, and HSCs followed by donor HSC transplantation enabled stable hematopoietic system reconstitution in recipients with mismatches at half (haploidentical) or all major histocompatibility complex (MHC) genes. This approach allowed tolerance to heart tissue from HSC donor strains in haploidentical recipients, showing potential applications for solid organ transplantation without immune suppression. Fully mismatched chimeric mice developed antibody responses to nominal antigens, showing preserved functional immunity. These findings suggest approaches for transplanting immunologically mismatched HSCs and solid organs with limited toxicity. 10.1016/j.stem.2019.05.018
    Adoptive T Cell Therapy Following Haploidentical Hematopoietic Stem Cell Transplantation. Zhang Ping,Tey Siok-Keen Frontiers in immunology Delayed immune reconstitution and the consequently high rates of leukemia relapse and infectious complications are the main limitations of haploidentical hematopoietic stem cell transplantation. Donor T cell addback can accelerate immune reconstitution but the therapeutic window between graft-vs.-host disease and protective immunity is very narrow in the haploidentical transplant setting. Hence, strategies to improve the safety and efficacy of adoptive T cell transfer are particularly relevant in this setting. Adoptive T cell transfer strategies in haploidentical transplantation include the use of antigen-specific T cells, allodepletion and alloanergy induction, immune modulation by the co-infusion of regulatory cell populations, and the use of safety switch gene-modified T cells. Whilst common principles apply, there are features that are unique to haploidentical transplantation, where HLA-mismatching directly impacts on immune reconstitution, and shared vs. non-shared HLA-allele can be an important consideration in antigen-specific T cell therapy. This review will also present an update on safety switch gene-modified T cells, which can be conditionally deleted in the event of severe graft- vs.-host disease or other adverse events. Herpes Virus Simplex Thymidine Kinase (HSVtk) and inducible caspase-9 (iCasp9) are safety switches that have undergone multicenter studies in haploidentical transplantation with encouraging results. These gene-modified cells, which are trackable long-term, have also provided important insights on the fate of adoptively transferred T cells. In this review, we will discuss the biology of post-transplant T cell immune reconstitution and the impact of HLA-mismatching, and the different cellular therapy strategies that can help accelerate T cell immune reconstitution after haploidentical transplantation. 10.3389/fimmu.2019.01854
    Hematopoietic stem cell transplantation using single UM171-expanded cord blood: a single-arm, phase 1-2 safety and feasibility study. Cohen Sandra,Roy Jean,Lachance Silvy,Delisle Jean-Sébastien,Marinier Anne,Busque Lambert,Roy Denis-Claude,Barabé Frédéric,Ahmad Imran,Bambace Nadia,Bernard Léa,Kiss Thomas,Bouchard Philippe,Caudrelier Pierre,Landais Sévérine,Larochelle Fannie,Chagraoui Jalila,Lehnertz Bernhard,Corneau Sophie,Tomellini Elisa,van Kampen Jeroen J A,Cornelissen Jan J,Dumont-Lagacé Maude,Tanguay Mégane,Li Qi,Lemieux Sébastien,Zandstra Peter W,Sauvageau Guy The Lancet. Haematology BACKGROUND:Benefits of cord blood transplantation include low rates of relapse and chronic graft-versus-host disease (GVHD). However, the use of cord blood is rapidly declining because of the high incidence of infections, severe acute GVHD, and transplant-related mortality. UM171, a haematopoietic stem cell self-renewal agonist, has been shown to expand cord blood stem cells and enhance multilineage blood cell reconstitution in mice. We aimed to investigate the safety and feasibility of single UM171-expanded cord blood transplantation in patients with haematological malignancies who do not have a suitable HLA-matched donor. METHODS:This single-arm, open-label, phase 1-2 safety and feasibility study was done at two hospitals in Canada. The study had two parts. In part 1, patients received two cord blood units (one expanded with UM171 and one unmanipulated cord blood) until UM171-expanded cord blood demonstrated engraftment. Once engraftment was documented we initiated part 2, reported here, in which patients received a single UM171-expanded cord blood unit with a dose de-escalation design to determine the minimal cord blood unit cell dose that achieved prompt engraftment. Eligible patients were aged 3-64 years, weighed 12 kg or more, had a haematological malignancy with an indication for allogeneic hematopoietic stem cell transplant and did not have a suitable HLA-matched donor, and a had a Karnofsky performance status score of 70% or more. Five clinical sites were planned to participate in the study; however, only two study sites opened, both of which only treated adult patients, thus no paediatric patients (aged <18 years) were recruited. Patients aged younger than 50 years without comorbidities received a myeloablative conditioning regimen (cyclophosphamide 120 mg/kg, fludarabine 75 mg/m, and 12 Gy total body irradiation) and patients aged older than 50 years and those with comorbidities received a less myeloablative conditioning regimen (cyclophosphamide 50 mg/kg, thiotepa 10 mg/kg, fludarabine 150 mg/m, and 4 Gy total body irradiation). Patients were infused with the 7-day UM171-expanded CD34-positive cells and the lymphocyte-containing CD34-negative fraction. The primary endpoints were feasibility of UM171 expansion, safety of the transplant, kinetics of hematopoietic reconstitution (time to neutrophil and platelet engraftment) of UM171-expanded cord blood, and minimal pre-expansion cord blood unit cell dose that achieved prompt engraftment. We analysed feasibility in all enrolled patients and all other primary outcomes were analysed per protocol, in all patients who received single UM171-expanded cord blood transplantation. This trial has been completed and was registered with ClinicalTrials.gov, NCT02668315. FINDINGS:Between Feb 17, 2016, and Nov 11, 2018, we enrolled 27 patients, four of whom received two cord blood units for safety purposes in part 1 of the study. 23 patients were subsequently enrolled in part 2 to receive a single UM171-expanded cord blood transplant and 22 patients received a single UM171-expanded cord blood transplantation. At data cutoff (Dec 31, 2018), median follow-up was 18 months (IQR 12-22). The minimal cord blood unit cell dose at thaw that achieved prompt engraftment as a single cord transplant after UM171 expansion was 0·52 × 10 CD34-positive cells. We successfully expanded 26 (96%) of 27 cord blood units with UM171. Among the 22 patients who received single UM171-expanded cord blood transplantation, median time to engraftment of 100 neutrophils per μL was 9·5 days (IQR 8-12), median time to engraftment of 500 neutrophils per μL was 18 days (12·5-20·0), and no graft failure occurred. Median time to platelet recovery was 42 days (IQR 35-47). The most common non-haematological adverse events were grade 3 febrile neutropenia (16 [73%] of 22 patients) and bacteraemia (nine [41%]). No unexpected adverse events were observed. One (5%) of 22 patients died due to treatment-related diffuse alveolar haemorrhage. INTERPRETATION:Our preliminary findings suggest that UM171 cord blood stem cell expansion is feasible, safe, and allows for the use of small single cords without compromising engraftment. UM171-expanded cord blood might have the potential to overcome the disadvantages of other cord blood transplants while maintaining the benefits of low risk of chronic GVHD and relapse, and warrants further investigation in randomised trials. FUNDING:Canadian Institutes of Health Research, Canadian Cancer Society and Stem Cell Network. 10.1016/S2352-3026(19)30202-9
    Early and Long-Term Impaired T Lymphocyte Immune Reconstitution after Cord Blood Transplantation with Antithymocyte Globulin. Castillo Nerea,García-Cadenas Irene,Barba Pere,Canals Carme,Díaz-Heredia Cristina,Martino Rodrigo,Ferrà Christelle,Badell Isabel,Elorza Izaskun,Sierra Jorge,Valcárcel David,Querol Sergio Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Immune reconstitution is crucial to the success of allogeneic hematopoietic stem cell transplantation. Umbilical cord blood transplantation (UCBT) has been associated with delayed immune reconstitution. We characterized the kinetics and investigated the risk variables affecting recovery of the main lymphocyte subsets in 225 consecutive pediatric and adult patients (males, n = 126; median age, 15; range, .3 to 60; interquartile range, 4 to 35) who underwent myeloablative single UCBT between 2005 and 2015 for malignant and nonmalignant disorders. Low CD4 and CD8 T cell counts were observed up to 12 months after UCBT. In contrast, B and natural killer cells recovered rapidly early after transplantation. In a multivariate regression model, factors favoring CD4 T cell recovery ≥ 200 cells/µL were lower dose antithymocyte globulin (ATG) (hazard ratio [HR], 3.93; 95% confidence interval [CI], 2.3 to 5.83; P = .001), negative recipient cytomegalovirus (CMV) serostatus (HR, 3.76; 95% CI, 1.9 to 5.74; P = .001), and younger age (HR, 2.61; 95% CI, 1.01 to 3.47; P = .03). Factors favoring CD8 T cell recovery ≥ 200 cells/µL were lower dose ATG (HR, 3.03; 95% CI, 1.4 to 5.1; P = .03) and negative recipient CMV serostatus (HR, 1.9; 95% CI, 1.63 to 2.15; P = .01). Our results demonstrate the significant negative impact of ATG on lymphocyte recovery. A reduction of the dose or omission of ATG could improve immune reconstitution and perhaps reduce opportunistic infections after UCBT. 10.1016/j.bbmt.2016.11.014
    Development of Three Different NK Cell Subpopulations during Immune Reconstitution after Pediatric Allogeneic Hematopoietic Stem Cell Transplantation: Prognostic Markers in GvHD and Viral Infections. Huenecke Sabine,Cappel Claudia,Esser Ruth,Pfirrmann Verena,Salzmann-Manrique Emilia,Betz Sibille,Keitl Eileen,Banisharif-Dehkordi Julia,Bakhtiar Shahrzad,Königs Christoph,Jarisch Andrea,Soerensen Jan,Ullrich Evelyn,Klingebiel Thomas,Bader Peter,Bremm Melanie Frontiers in immunology Natural killer (NK) cells play an important role following allogeneic hematopoietic stem cell transplantation (HSCT) exerting graft-versus-leukemia/tumor effect and mediating pathogen-specific immunity. Although NK cells are the first donor-derived lymphocytes reconstituting post-HSCT, their distribution of CD56CD16 (CD56), CD56CD16 (CD56), and CD56CD16 (CD56) NK cells is explicitly divergent from healthy adults, but to some extent comparable to the NK cell development in early childhood. The proportion of CD56/CD56/CD56 changed from 15/8/78% in early childhood to 6/4/90% in adults, respectively. Within this study, we first compared the NK cell reconstitution post-HSCT to reference values of NK cell subpopulations of healthy children. Afterward, we investigated the reconstitution of NK cell subpopulations post-HSCT in correlation to acute graft versus host disease (aGvHD) and chronic graft versus host disease (cGvHD) as well as to viral infections. Interestingly, after a HSCT follow-up phase of 12 months, the distribution of NK cell subpopulations largely matched the 50th percentile of the reference range for healthy individuals. Patients suffering from aGvHD and cGvHD showed a delayed reconstitution of NK cells. Remarkably, within the first 2 months post-HSCT, patients suffering from aGvHD had significantly lower levels of CD56 NK cells compared to patients without viral infection or without graft versus host disease (GvHD). Therefore, the amount of CD56 NK cells might serve as an early prognostic factor for GvHD development. Furthermore, a prolonged and elevated peak in CD56 NK cells seemed to be characteristic for the chronification of GvHD. In context of viral infection, a slightly lower CD56 and CD16 receptor expression followed by a considerable reduction in the absolute CD56 NK cell numbers combined with reoccurrence of CD56 NK cells was observed. Our results suggest that a precise analysis of the reconstitution of NK cell subpopulations post-HSCT might indicate the occurrence of undesired events post-HSCT such as severe aGvHD. 10.3389/fimmu.2017.00109
    Immune reconstitution and outcomes after conditioning with anti-thymocyte-globulin in unrelated cord blood transplantation; the good, the bad, and the ugly. de Koning Coco,Admiraal Rick,Nierkens Stefan,Boelens Jaap Jan Stem cell investigation Unrelated umbilical cord blood transplantation (UCBT) exhibits a low risk of graft-versus-host-disease (GvHD) and has unique potent anti-virus and anti-leukemia effects. Anti-thymocyte globulin (ATG) in the conditioning regimen for UCBT is successful in reducing graft rejection and GvHD. Nevertheless, this beneficial effect of ATG coincides with its detrimental effect on immune reconstitution. The latter directly relates to a high incidence of viral infections and leukemia relapses. ATG has been used in transplant patients for over 30 years. In recent years, the knowledge on the mechanisms of action of ATG and its implementation in the UCBT setting has increased dramatically. Important data became available showing the highly variable pharmacokinetics (PK) of ATG and its consequence on outcome measures. Here, we review the effects of ATG on immune reconstitution and subsequent outcomes after UCBT, and describe the mechanisms causing these effects. We highlight the importance of optimizing ATG exposure before and after UCBT and discuss strategies to maintain the 'good' and overcome the 'bad and ugly' effects of ATG on UCBT outcome. 10.21037/sci.2017.05.02
    Immune reconstitution with two different rabbit polyclonal anti-thymocytes globulins. Bamoulid Jamal,Crepin Thomas,Gaiffe Emilie,Laheurte Caroline,Moulin Bruno,Frimat Luc,Rieu Philippe,Mousson Christiane,Durrbach Antoine,Heng Anne-Elisabeth,Rebibou Jean-Michel,Saas Philippe,Courivaud Cécile,Ducloux Didier Transplant immunology Broad T cell depletion by polyclonal anti-thymocyte globulins (ATG) has been used for many years as a part of immunosuppressive treatment in transplantation. Currently, two different ATG are used in clinical practice, Thymoglobulin and Grafalon. Due to differences in the immunization source, these products contain different specificities and quantity of antibodies. These differences may have clinical consequences. We conducted a nested study in a large prospective multicentric cohort of kidney transplant to determine whether Grafalon-treated and Thymoglobulin-treated patients experience different lymphocyte reconstitution and clinical outcomes. 182 patients matched for age, gender, CMV status, CMV prophylaxis, number of previous transplantation, and maintenance immunosuppressive treatment were included (Thymoglobulin, [n=91]; Grafalon®, [n=91]). One-year post-transplant, recent thymic emigrants were significantly decreased (12±10% vs 21±12%; p<0.001) in Grafalon-treated patients. By contrast, T cell activation (CD38+DR+Ki67+) and senescence (CD8+CD57+CD28-) was increased in Thymoglobulin-treated patients. Compared to Grafalon, Thymoglobulin was not associated with a significantly different rate of acute rejection. CMV disease (p=0.013) was more frequent in Thymoglobulin-treated patients. Grafalon and Thymoglobulin seem to be equivalent to prevent acute rejection. CMV disease is more frequent in Thymoglobulin-treated patients. One year post-transplant immune profile profoundly differs according to the type of ATG. 10.1016/j.trim.2017.09.002
    Cord blood transplantation recapitulates fetal ontogeny with a distinct molecular signature that supports CD4 T-cell reconstitution. Hiwarkar Prashant,Hubank Mike,Qasim Waseem,Chiesa Robert,Gilmour Kimberly C,Saudemont Aurore,Amrolia Persis J,Veys Paul Blood advances Omission of in vivo T-cell depletion promotes rapid, thymic-independent CD4-biased T-cell recovery after cord blood transplant. This enhanced T-cell reconstitution differs from that seen after stem cell transplant from other stem cell sources, but the mechanism is not known. Here, we demonstrate that the transcription profile of naive CD4 T cells from cord blood and that of lymphocytes reconstituting after cord blood transplantation is similar to the transcription profile of fetal CD4 T cells. This profile is distinct to that of naive CD4 T cells from peripheral blood and that of lymphocytes reconstituting after T-replete bone marrow transplantation. The transcription profile of reconstituting naive CD4 T cells from cord blood transplant recipients was upregulated in the T-cell receptor (TCR) signaling pathway and its transcription factor activator protein-1 (AP-1). Furthermore, a small molecule inhibitor of AP-1 proportionally inhibited cord blood CD4 T-cell proliferation ( < .05). Together, these findings suggest that reconstituting cord blood CD4 T cells reflect the properties of fetal ontogenesis, and enhanced TCR signaling is responsible for the rapid restoration of the unique CD4 T-cell biased adaptive immunity after cord blood transplantation. 10.1182/bloodadvances.2017010827
    Mucosal-Associated Invariant T Cells Display a Poor Reconstitution and Altered Phenotype after Allogeneic Hematopoietic Stem Cell Transplantation. Solders Martin,Erkers Tom,Gorchs Laia,Poiret Thomas,Remberger Mats,Magalhaes Isabelle,Kaipe Helen Frontiers in immunology Mucosal-associated invariant T (MAIT) cells are innate-like T cells which are important in the defense against certain bacteria and yeast. The reconstitution of MAIT cells after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We investigated MAIT cell phenotype and function in 17 patients devoid of relapse and severe graft-versus-host disease (GvHD) in paired samples collected 1-2, 3-6, 12, and 24 months after transplantation. Data were compared to 17 healthy controls (HC), as well as 22 patients with acute GvHD grade 2-3. The frequency of MAIT cells within CD3 cells was approximately 10-fold lower than in HC and did not increase over the 2 years following HSCT. MAIT cells in HSCT patients displayed an elevated expression of CD69 and intracellular granzyme B and were predominantly composed of CD4/CD8 double-negative cells. The expression of PD-1 on MAIT cells was low and did not change during the observational time, whereas the CD3CD161TCRVα7.2 cells (non-MAIT T cells) displayed a high expression early after HSCT that decreased to normal levels at 24 months. MAIT cells collected 2-6 months post-HSCT showed an impaired IFN-γ and perforin response after bacterial stimulation, but the response was restored at 24 months. Patients with acute GvHD had similar proportions of MAIT cells as patients with grade 0-1, but consisted mainly of CD8 cells. Finally, MAIT cells were more sensitive to cyclosporine A and sirolimus than non-MAIT T cells. To conclude, MAIT cell reconstitution following HSCT is deficient compared to non-MAIT T cells and GvHD grade ≥2 is not correlated with MAIT cell frequency. MAIT cell functionality was impaired early after HSCT, but restored at 24 months post-HSCT. MAIT cells have an increased sensibility to common immunosuppressive drugs, which maybe could explain their hampered reconstitution after HSCT. 10.3389/fimmu.2017.01861
    Have haploidentical transplants replaced umbilical cord transplants for acute leukemias? Liu Jia Hau,Kanakry Christopher G,Luznik Leo Current opinion in hematology PURPOSE OF REVIEW:Haploidentical stem cell transplantation (Haplo SCT) and umbilical cord blood stem cell transplantation (UCB SCT) have emerged over the past two to three decades as viable sources of alternative donor SCT when a human leukocyte antigen matched donor is not available. However, which of these two donor types is optimal for patients with leukemia in need of allografting is unknown. RECENT FINDINGS:For patients with acute leukemia, results of UCB SCT have been improved by the use of double umbilical cord units and emerging ex-vivo expansion technologies. However, the costs associated with procuring double cord units and high transplant-related mortality due to delayed immunological reconstitution and infections, particularly in adult patients, remain a problem. Recently, Haplo SCT has become an increasingly utilized alternative donor source. While improvements of ex-vivo T-cell depletion platforms continue, emergence of T-cell-replete platforms, such as the use of post-transplantation cyclophosphamide (PTCy), is increasingly being utilized in treating acute leukemia patients. PTCy-based Haplo SCT is gaining popularity among transplant clinicians due to its relatively easy learning curve, low cost, low incidence of graft-versus-host disease, and favorable survival in acute leukemia patients. SUMMARY:The clinical question of whether Haplo SCT should replace UCB SCT needs to be answered by ongoing randomized trials. However, the rapidly increasing adoption of Haplo SCT worldwide as the viable alternative for patients without a human leukocyte antigen-matched donor has seemingly addressed the question ahead of scientific judgment. 10.1097/MOH.0000000000000412
    Rapid reconstitution of NK1 cells after allogeneic transplantation is associated with a reduced incidence of graft-versus-host disease. Yu Xingxing,Xu Lingling,Chang Yingjun,Huang Xiaojun,Zhao Xiangyu Science China. Life sciences The balance between immunostimulation and immunoregulation in T cell immunity is achieved by maintaining specific ratios of Th1, Th2, Th3 and Tr1 cells. Here, we investigate levels of type 1 (IFN-gamma; NK1), type 2 (IL-13; NK2), type 3 (TGF-beta; NK3) and regulatory (IL-10; NKr) cytokines in peripheral blood to assess the cytokine profiles of natural killer (NK) cells following human allogeneic hematopoietic stem cell transplantation (allo-HSCT). NK2 and NK3 cell expansion was observed after allo-HSCT; levels of NKr cells reached donor levels at day 15, though levels of NK1 cells were consistently lower than donor levels until day 60 after allo-HSCT. Multivariate analysis showed that a higher level of NK1 cells by day 15 was associated with a lower overall risk of acute graft-versus-host disease (GVHD) (HR 0.157, P=0.010) as well as II-IV acute GVHD (HR 0.260, P=0.059). Furthermore, higher levels of NK1 cells by day 15 were correlated with lower rates of cytomegalovirus (CMV) reactivation (HR 0.040, 0.005-0.348, P=0.003). These results indicate that rapid reconstitution of NK cells, especially NK1 cells, can help prevent the development of GVHD as well as CMV reactivation after allogeneic transplantation. 10.1007/s11427-017-9160-3
    Control of Cytomegalovirus Viremia after Allogeneic Stem Cell Transplantation: A Review on CMV-Specific T Cell Reconstitution. van der Heiden Pim,Marijt Erik,Falkenburg Fred,Jedema Inge Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Recipients of allogeneic stem cell transplantation (alloSCT) are at risk for reactivation of endogenous herpesviruses due to profound and prolonged T cell deficiency following conditions such as graft-versus-host disease, immunosuppression, and/or T cell depletion. Reactivation of endogenous cytomegalovirus (CMV) is the most frequently occurring herpesvirus reactivation following alloSCT. Antiviral medication is often used in pre-emptive treatment strategies initiated when increases in CMV viral loads are detected as a result of active reactivation of the virus. Despite pre-emptive antiviral treatment, the incidence of CMV disease in CMV-seropositive alloSCT patients is still 10% at 1 year following alloSCT. This illustrates the necessity for adequate CMV-specific T cell immunity for long-term control of CMV and prevention of CMV disease. In this review, we analyzed the available studies on the influence of donor CMV status on CMV-specific T cell reconstitution and CMV disease. Furthermore, we reviewed the available studies on the safety and efficacy of adoptive transfer of donor CMV-specific T cells for the prevention and treatment of CMV disease following alloSCT, including studies on adoptive transfer of third-party CMV-specific T cells as a possible alternative when donor T cells are not available. 10.1016/j.bbmt.2018.03.028
    Haploidentical Hematopoietic Stem Cell Transplantation with Post-Transplant Cyclophosphamide for Primary Immunodeficiencies and Inherited Disorders in Children. Neven Bénédicte,Diana Jean-Sébastien,Castelle Martin,Magnani Alessandra,Rosain Jérémie,Touzot Fabien,Moreira Baptiste,Fremond Marie-Louise,Briand Coralie,Bendavid Matthieu,Levy Romain,Morelle Guillaume,Vincent Marc,Magrin Elsa,Bourget Philippe,Chatenoud Lucienne,Picard Capucine,Fischer Alain,Moshous Despina,Blanche Stéphane Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for some inherited disorders, including selected primary immunodeficiencies (PIDs). In the absence of a well-matched donor, HSCT from a haploidentical family donor (HIFD) may be considered. In adult recipients high-dose post-transplant cyclophosphamide (PTCY) is increasingly used to mitigate the risks of graft failure and graft-versus-host disease (GVHD). However, data on the use of PTCY in children (and especially those with inherited disorders) are scarce. We reviewed the outcomes of 27 children transplanted with an HIFD and PTCY for a PID (n = 22) or osteopetrosis (n = 5) in a single center. The median age was 1.5 years (range, .2 to 17). HSCT with PTCY was a primary procedure (n = 21) or a rescue procedure after graft failure (n = 6). The conditioning regimen was myeloablative in most primary HSCTs and nonmyeloablative in rescue procedures. After a median follow-up of 25.6 months, 24 of 27 patients had engrafted. Twenty-one patients are alive and have been cured of the underlying disease. The 2-year overall survival rate was 77.7%. The cumulative incidences of acute GVHD grade ≥ II, chronic GVHD, and autoimmune disease were 45.8%, 24.2%, and 29.6%, respectively. There were 2 cases of grade III acute GVHD and no extensive cGVHD. The cumulative incidences of blood viral replication and life-threatening viral events were 58% and 15.6%, respectively. There was evidence of early T cell immune reconstitution. In the absence of an HLA-identical donor, HIFD HSCT with PTCY is a viable option for patients with life-threatening inherited disorders. 10.1016/j.bbmt.2019.03.009
    NK cell reconstitution following unmanipulated HLA-mismatched/haploidentical transplantation compared with matched sibling transplantation. Hu Li-Juan,Cao Xun-Hong,Yu Xing-Xing,Liu Xue-Fei,Zhao Xiao-Su,Chang Ying-Jun,Zhang Xiao-Hui,Xu Lan-Ping,Wang Yu,Liu Kai-Yan,Huang Xiao-Jun,Zhao Xiang-Yu Science China. Life sciences 10.1007/s11427-018-9565-5
    Haploidentical hematopoietic stem cell transplantation with post-transplant high-dose cyclophosphamide in high-risk children: A single-center study. Uygun Vedat,Karasu Gülsün,Daloğlu Hayriye,Öztürkmen Seda,Çakı Kılıç Suar,Hazar Volkan,Yeşilipek Akif Pediatric transplantation BACKGROUND:Post-Cy administration for GVHD prophylaxis in unmanipulated haploidentical HSCT has resulted in improved outcomes in recent years. Studies in children are lacking and accordingly we present the outcomes of 62 haploidentical transplantation for high-risk children. PROCEDURE:We retrospectively assessed 62 transplants in 60 patients who underwent haploidentical-related HSCT with unmanipulated stem cells and for whom Post-Cy was used for GVHD prophylaxis. RESULTS:Myeloid reconstitution was achieved on day + 30 for 57 of the 62 patients. The median follow-up of the surviving 39 patients (63%) was 26 months, with a range of 6-57 months. The OS and EFS at 2 years were 64.6% (52.0%-77.2%, 95% CI) and 58.9% (46.1%-71.7%, 95% CI), respectively. The only factor in our multivariate analysis that contributed to an inferior EFS was a poor remission status prior to HSCT (HR, 8.30; 1.08-63.56; P = 0.041, 95% CI). CONCLUSION:The results of T-cell replete haploidentical transplantation with Post-Cy GVHD prophylaxis in high-risk pediatric patients are promising. However, further research is needed to determine the factors that have affect HLA compatibility for predicting the success of haploidentical transplantations. 10.1111/petr.13546
    Impaired lymphocyte reconstitution after autologous transplant is associated with apoptosis of CD8+ T cells and adverse clinical outcome. Rozovski Uri,Naparstek Ella,Frank Shani,Fourman Alexey,Zigman-Hoffman Eti,Bleiberg Margalit,Yeshurun Moshe,Trestman Svetlana,Tartakovsky Boris Leukemia & lymphoma We noticed that the lymphocyte counts, after autologous hematopoietic stem cell transplantation, oscillated during the first 4 post-transplant months. Thereafter, the lymphocyte counts stabilized and segregated the patients into two groups, those who normalized their lymphocyte counts and those with prolonged lymphopenia. In both groups, the CD4 counts remained low for at least 6 months. However, in approximately half of the patient, the CD8 counts increased to normal or above normal values. Patients with prolonged lymphopenia had higher rates of lymphocytes' spontaneous apoptosis and the lymphocytes in patients who restored their counts expressed the intracellular CD14-derived MO2 epitope that protects the cells from apoptosis. These findings were translated to longer disease-free survival and overall survival in patients who restored the CD8 counts. Collectively, our data show that post-transplant lymphocytes that express intracellular CD14-MO2 epitope have survival advantage. 10.1080/10428194.2018.1563696
    Improving engraftment and immune reconstitution in umbilical cord blood transplantation. Danby Robert,Rocha Vanderson Frontiers in immunology Umbilical cord blood (UCB) is an important source of hematopoietic stem cells (HSC) for allogeneic transplantation when HLA-matched sibling and unrelated donors (MUD) are unavailable. Although the overall survival results for UCB transplantation are comparable to the results with MUD, UCB transplants are associated with slow engraftment, delayed immune reconstitution, and increased opportunistic infections. While this may be a consequence of the lower cell dose in UCB grafts, it also reflects the relative immaturity of cord blood. Furthermore, limited cell numbers and the non-availability of donor lymphocyte infusions currently prevent the use of post-transplant cellular immunotherapy to boost donor-derived immunity to treat infections, mixed chimerism, and disease relapse. To further develop UCB transplantation, many strategies to enhance engraftment and immune reconstitution are currently under investigation. This review summarizes our current understanding of engraftment and immune recovery following UCB transplantation and why this differs from allogeneic transplants using other sources of HSC. It also provides a comprehensive overview of promising techniques being used to improve myeloid and lymphoid recovery, including expansion, homing, and delivery of UCB HSC; combined use of UCB with third-party donors; isolation and expansion of natural killer cells, pathogen-specific T cells, and regulatory T cells; methods to protect and/or improve thymopoiesis. As many of these strategies are now in clinical trials, it is anticipated that UCB transplantation will continue to advance, further expanding our understanding of UCB biology and HSC transplantation. 10.3389/fimmu.2014.00068
    Association between anti-thymocyte globulin exposure and CD4+ immune reconstitution in paediatric haemopoietic cell transplantation: a multicentre, retrospective pharmacodynamic cohort analysis. Admiraal Rick,van Kesteren Charlotte,Jol-van der Zijde Cornelia M,Lankester Arjan C,Bierings Marc B,Egberts Toine C G,van Tol Maarten J D,Knibbe Catherijne A J,Bredius Robbert G M,Boelens Jaap J The Lancet. Haematology BACKGROUND:Anti-thymocyte globulin (ATG) was introduced into the conditioning regimen in haemopoietic cell transplantation (HCT) to prevent graft-versus-host-disease (GvHD) and graft failure. However, ATG can also cause delayed immune reconstitution of donor T cells. We studied the relation between exposure to active ATG and clinical outcomes in children. METHODS:In this retrospective analysis, all patients (age 0·2-23 years) receiving their first HCT between April 1, 2004, and April 1, 2012, who received ATG (thymoglobulin) in two Dutch paediatric HCT programmes were included. The cumulative dose of ATG was chosen according to local protocols and was given intravenously over 4 days consecutively. ATG exposure measures (maximum concentration, concentration at time of HCT, clearance, days to reach a concentration below the lympholytic concentration of one arbitrary unit [AU] per mL, total area under the curve [AUC], AUC before HCT, and AUC after HCT) were calculated using a validated population pharmacokinetic model. The main outcome of interest was immune reconstitution (defined as CD4+ T cells >0·05 × 10(9) cells per L in two consecutive measurements within 100 days). Other outcomes of interest were survival, acute and chronic GvHD, and graft failure. We used Cox proportional hazard models, logistic regression models, and Fine-Gray competing risk regressions for analyses. FINDINGS:251 patients were included. The chance of successful immune reconstitution decreased as the ATG AUC after HCT increased (odds ratio 0·991, 95% CI 0·987-0·996; p<0·0001). Within the cord blood group, we noted decreased immune reconstitution above the lowest AUC quartile (≥ 20 AU × day/mL; p=0·0024), whereas in the bone marrow or peripheral blood stem cell group, decreased immune reconstitution was noted only in the highest quartile (≥ 100 AU × day/mL; p=0·0024). Successful immune reconstitution by day 100 was associated with increased overall survival (hazard ratio [HR] 0·49, 95% CI 0·29-0·81; p=0·0047) caused by reduced non-relapse mortality (0·40, 0·21-0·77; p=0·0062), and relapse-related mortality in myeloid leukaemia (0·25, 0·08-0·76; p=0·015). An AUC before transplantation of at least 40 AU × day/mL resulted in a lower incidence of acute GvHD (grade 2-4 HR 0·979, 95% CI 0·963-0·994; p=0·0081; and grade 3-4 0·975, 0·952-0·998; p=0·033), chronic GvHD (0·983, 0·968-0·998; p=0·029), and graft failure (0·981, 0·965-0·997; p=0·020) compared with an AUC of less than 40 AU × day/mL. INTERPRETATION:These results stress the importance of improving the efficacy and safety of ATG in HCT by amending dosage and timing. Individualised dosing and timing of ATG to aim for optimum exposure before and after HCT could result in improved outcomes after paediatric HCT. FUNDING:Dutch Organization for Scientific Research. 10.1016/S2352-3026(15)00045-9
    Mesenchymal stromal cells improve early lymphocyte recovery and T cell reconstitution after autologous hematopoietic stem cell transplantation in patients with malignant lymphomas. Batorov Egor V,Shevela Ekaterina Ya,Tikhonova Marina A,Batorova Dariya S,Ushakova Galina Yu,Sizikova Svetlana A,Sergeevicheva Vera V,Gilevich Andrey V,Kryuchkova Irina V,Ostanin Alexandr A,Chernykh Elena R Cellular immunology Mesenchymal stromal cells (MSCs) possess a multi-lineage potential and immunoregulatory activities and provide a great potential in cell-based technologies. However, MSC suppressive activity raises concerns regarding the possible adverse effect of MSCs on the immune recovery. The influence of autologous MSC co-transplantation on recovery of T cell subsets in patients receiving autologous hematopoietic stem cell transplantation (AHSCT) for malignant lymphomas and multiple myeloma were characterized. Co-transplantation of MSCs improved lymphocyte recovery most effectively in patients with low input of hematopoietic stem cells or low absolute lymphocyte count in apheresis product. MSC co-transplantation improved early recovery of both memory and naive T cells with more prominent effect on naive CD4(+) T cells. Patients with MSC co-transplantation showed more effective reconstitution of recent thymic emigrants. These data indicate the positive impact of MSCs on immune reconstitution and note MSC co-transplantation is feasible to optimize the outcomes of AHSCT in malignant lymphoma patients. 10.1016/j.cellimm.2015.07.001
    Pretransplant CD4 Count Influences Immune Reconstitution and Risk of Infectious Complications in Human Immunodeficiency Virus-Infected Kidney Allograft Recipients. Suarez J F,Rosa R,Lorio M A,Morris M I,Abbo L M,Simkins J,Guerra G,Roth D,Kupin W L,Mattiazzi A,Ciancio G,Chen L J,Burke G W,Goldstein M J,Ruiz P,Camargo J F American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons In current practice, human immunodeficiency virus-infected (HIV(+) ) candidates with CD4 >200 cells/mm(3) are eligible for kidney transplantation; however, the optimal pretransplant CD4 count above this threshold remains to be defined. We evaluated clinical outcomes in patients with baseline CD4 >350 and <350 cells/mm(3) among 38 anti-thymocyte globulin (ATG)-treated HIV-negative to HIV(+) kidney transplants performed at our center between 2006 and 2013. Median follow-up was 2.6 years. Rates of acute rejection and patient and graft survival were not different between groups. Occurrence of severe CD4 lymphopenia (<200 cells/mm(3) ), however, was more common among patients with a baseline CD4 count 200-349 cells/mm(3) compared with those transplanted at higher counts (75% vs. 30% at 4 weeks [p = 0.04] and 71% vs. 5% at 52 weeks [p = 0.001], respectively, after transplant). After adjusting for age, baseline CD4 count of 200-349 cells/mm(3) was an independent predictor of severe CD4 lymphopenia at 4 weeks (relative risk [RR] 2.6; 95% confidence interval [CI] 1.3-5.1) and 52 weeks (RR 14.3; 95% CI 2-100.4) after transplant. Patients with CD4 <200 cells/mm(3) at 4 weeks had higher probability of serious infections during first 6 months after transplant (19% vs. 50%; log-rank p = 0.05). These findings suggest that ATG must be used with caution in HIV(+) kidney allograft recipients with a pretransplant CD4 count <350 cells/mm(3) . 10.1111/ajt.13782
    Strategies before, during, and after hematopoietic cell transplantation to improve T-cell immune reconstitution. de Koning Coco,Nierkens Stefan,Boelens Jaap Jan Blood T-cell immune reconstitution (IR) after allogeneic hematopoietic cell transplantation (allo-HCT) is highly variable between patients and may take several months to even years. Patients with delayed or unbalanced T-cell IR have a higher probability of developing transplantation-related morbidity, mortality, and relapse of disease. Hence, there is a need for strategies to better predict and improve IR to reduce these limitations of allo-HCT. In this review, we provide an update of current and in-near-future clinically relevant strategies before, during, and after transplantation to achieve successful T-cell IR. Potent strategies are choosing the right HCT source (eg, donor-recipient matching, cell dose, graft manipulation), individualized conditioning and serotherapy (eg, antithymocyte globulin), nutritional status, exercise, home care, modulation of microbiota, enhancing homeostatic peripheral expansion, promoting thymopoiesis, and the use of adjuvant-targeted cellular immunotherapies. Strategies to prevent graft-versus-host disease are important as well because this complication and the subsequent need for immunosuppression affects T-cell IR and function. These options aim for personalized precision transplantation, where allo-HCT therapy is designed to boost a well-balanced T-cell IR and limit complications in individual patients, resulting in overall lower morbidity and higher survival chances. 10.1182/blood-2016-06-724005
    Immune Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation: Time To T Up the Thymus. Chaudhry Mohammed S,Velardi Enrico,Malard Florent,van den Brink Marcel R M Journal of immunology (Baltimore, Md. : 1950) The success of allogeneic hematopoietic stem cell transplantation, a key treatment for many disorders, is intertwined with T cell immune reconstitution. The thymus plays a key role post allogeneic hematopoietic stem cell transplantation in the generation of a broad but self-tolerant T cell repertoire, but it is exquisitely sensitive to a range of insults during the transplant period, including conditioning regimens, corticosteroids, infections, and graft-versus-host disease. Although endogenous thymic repair is possible it is often suboptimal, and there is a need to develop exogenous strategies to help regenerate the thymus. Therapies currently in clinical trials in the transplant setting include keratinocyte growth factor, cytokines (IL-7 and IL-22), and hormonal modulation including sex steroid inhibition and growth hormone administration. Such regenerative strategies may ultimately enable the thymus to play as prominent a role after transplant as it once did in early childhood, allowing a more complete restoration of the T cell compartment. 10.4049/jimmunol.1601100
    Current Knowledge and Priorities for Future Research in Late Effects after Hematopoietic Stem Cell Transplantation (HCT) for Severe Combined Immunodeficiency Patients: A Consensus Statement from the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects after Pediatric HCT. Heimall Jennifer,Puck Jennifer,Buckley Rebecca,Fleisher Thomas A,Gennery Andrew R,Neven Benedicte,Slatter Mary,Haddad Elie,Notarangelo Luigi D,Baker K Scott,Dietz Andrew C,Duncan Christine,Pulsipher Michael A,Cowan Mort J Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Severe combined immunodeficiency (SCID) is 1 of the most common indications for pediatric hematopoietic cell transplantation (HCT) in patients with primary immunodeficiency. Historically, SCID was diagnosed in infants who presented with opportunistic infections within the first year of life. With newborn screening (NBS) for SCID in most of the United States, the majority of infants with SCID are now diagnosed and treated in the first 3.5 months of life; however, in the rest of the world, the lack of NBS means that most infants with SCID still present with infections. The average survival for SCID patients who have undergone transplantation currently is >70% at 3 years after transplantation, although this can vary significantly based on multiple factors, including age and infection status at the time of transplantation, type of donor source utilized, manipulation of graft before transplantation, graft-versus-host disease prophylaxis, type of conditioning (if any) utilized, and underlying genotype of SCID. In at least 1 study of SCID patients who received no conditioning, long-term survival was 77% at 8.7 years (range out to 26 years) after transplantation. Although a majority of patients with SCID will engraft T cells without any conditioning therapy, depending on genotype, donor source, HLA match, and presence of circulating maternal cells, a sizable percentage of these will fail to achieve full immune reconstitution. Without conditioning, T cell reconstitution typically occurs, although not always fully, whereas B cell engraftment does not, leaving some molecular types of SCID patients with intrinsically defective B cells, in most cases, dependent on regular infusions of immunoglobulin. Because of this, many centers have used conditioning with alkylating agents including busulfan or melphalan known to open marrow niches in attempts to achieve B cell reconstitution. Thus, it is imperative that we understand the potential late effects of these agents in this patient population. There are also nonimmunologic risks associated with HCT for SCID that appear to be dependent upon the genotype of the patient. In this report, we have evaluated the published data on late effects and attempted to summarize the known risks associated with conditioning and alternative donor sources. These data, while informative, are also a clear demonstration that there is still much to be learned from the SCID population in terms of their post-HCT outcomes. This paper will summarize current findings and recommend further research in areas considered high priority. Specific guidelines regarding a recommended approach to long-term follow-up, including laboratory and clinical monitoring, will be forthcoming in a subsequent paper. 10.1016/j.bbmt.2016.12.619
    CD56-enriched donor cell infusion after post-transplantation cyclophosphamide for haploidentical transplantation of advanced myeloid malignancies is associated with prompt reconstitution of mature natural killer cells and regulatory T cells with reduced incidence of acute graft versus host disease: A pilot study. Jaiswal Sarita Rani,Zaman Shamsur,Nedunchezhian Murugaiyan,Chakrabarti Aditi,Bhakuni Prakash,Ahmed Margoob,Sharma Kanika,Rawat Sheh,O'donnell Paul,Chakrabarti Suparno Cytotherapy We conducted a pilot study on the feasibility of CD56-enriched donor cell infusion after post-transplantation cyclophosphamide (PTCy) for 10 patients with advanced myeloid malignancies undergoing haploidentical peripheral blood stem cell transplantation with cyclosporine alone as graft-versus-host disease (GVHD) prophylaxis and compared the outcome and immune reconstitution with a control group of 20 patients undergoing the same without CD56-enriched donor cell infusion. An early and rapid surge of mature NK cells as well as CD4 T cells and regulatory T cells (Tregs) was noted compared with the control group. KIR of donor phenotype reconstituted as early as day 30 with expression of CD56CD16NKG2AKIR phenotype. None experienced viral or fungal infections, and non-relapse mortality was 10% only. The incidence of grade 2-4 acute GVHD was 50% in the control group with none in the CD56 group (P = 0.01). Only two had de novo chronic GVHD in each group. Relapse occurred in five patients in CD56 group with a median follow-up of 12 months, similar to the control group. Our preliminary data show that CD56 donor cell infusion after PTCy and short-course cyclosporine is feasible with prompt engraftment, rapid reconstitution of CD4T cells, Tregs and NK cells and reduced incidence of acute GVHD. 10.1016/j.jcyt.2016.12.006
    Prophylactic oral NAC reduced poor hematopoietic reconstitution by improving endothelial cells after haploidentical transplantation. Kong Yuan,Wang Yu,Zhang Yuan-Yuan,Shi Min-Min,Mo Xiao-Dong,Sun Yu-Qian,Chang Ying-Jun,Xu Lan-Ping,Zhang Xiao-Hui,Liu Kai-Yan,Huang Xiao-Jun Blood advances Poor graft function (PGF) and prolonged isolated thrombocytopenia (PT) remain life-threatening complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Endothelial cells (ECs) play a crucial role in regulating hematopoiesis in the bone marrow (BM) microenvironment. However, whether the impaired BM ECs are responsible for defective hematopoiesis in PGF and PT patients requires clarification, and clinical management is challenging. Two prospective clinical trials were included in the current study. In the first trial (N = 68), PGF and PT patients demonstrated defective BM ECs pre-HSCT and impaired BM EC dynamic reconstitution at early time points post-HSCT, which was positively correlated with reactive oxygen species (ROS) levels. Receiver operating characteristic curves showed that BM EC < 0.1% pre-HSCT could identify high-risk patients with PGF and PT. The second trial enrolled patients (N = 35) with EC < 0.1% who accepted oral -acetyl-l-cysteine (NAC; 400 mg 3 times per day) from -14 days pre-HSCT to +2 months post-HSCT continuously, whereas the remaining EC ≥ 0.1% patients (N = 39) received allo-HSCT only. Prophylactic NAC intervention was safe and effective in preventing the occurrence of PGF and PT in EC < 0.1% patients by promoting the dynamic reconstitution of BM ECs and CD34 cells, along with reducing their ROS levels, which was further confirmed by in situ BM trephine biopsy analyses. These findings suggest that the impaired BM ECs pre-HSCT are responsible for the defective hematopoiesis in PGF and PT patients. Therefore, improvement of BM ECs through prophylactic NAC intervention may be a promising therapeutic approach to promote hematopoietic reconstitution post-HSCT. This trial was registered at www.clinicaltrials.gov as #NCT03236220 and #NCT02978274. 10.1182/bloodadvances.2018029454
    Ex vivo generated human T-lymphoid progenitors as a tool to accelerate immune reconstitution after partially HLA compatible hematopoietic stem cell transplantation or after gene therapy. André Isabelle,Simons Laura,Ma Kuiying,Moirangthem Ranjita Devi,Diana Jean-Sébastien,Magrin Elisa,Couzin Chloé,Magnani Alessandra,Cavazzana Marina Bone marrow transplantation Prolonged T-cell immunodeficiency following HLA- incompatible hematopoietic stem cell transplantation (HSCT) represents a major obstacle hampering the more widespread use of this approach. Strategies to fasten T-cell reconstitution in this setting are highly warranted as opportunistic infections and an increased risk of relapse account for high rates of morbidity and mortality especially during early month following this type of HSCT. We have implemented a feeder free cell system based on the use of the notch ligand DL4 and cytokines allowing for the in vitro differentiation of human T-Lymphoid Progenitor cells (HTLPs) from various sources of CD34+ hematopoietic stem and precursor cells (HSPCs). Co- transplantion of human T-lymphoid progenitors (HTLPs) and non- manipulated HSPCs into immunodeficient mice successfully accelerated the reconstitution of a polyclonal T-cell repertoire. This review summarizes preclinical data on the use of T-cell progenitors for treatment of post- transplantation immunodeficiency and gives insights into the development of GMP based protocols for potential clinical applications including gene therapy approaches. Future clinical trials implementing this protocol will aim at the acceleration of immune reconstitution in different clinical settings such as SCID and leukemia patients undergoing allogeneic transplantation. Apart from pure cell-therapy approaches, the combination of DL-4 culture with gene transduction protocols will open new perspectives in terms of gene therapy applications for primary immunodeficiencies. 10.1038/s41409-019-0599-9
    [Effects of High Cytomegalovirus DNA Load on Immune Reconstitution and Clinical Outcomes after Single Unrelated Cord Blood Transplantation]. Dong Man-Yu,Tang Bao-Lin,Zhu Xiao-Yu,Liu Hui-Lan,Sun Zi-Min Zhongguo shi yan xue ye xue za zhi OBJECTIVE:To investigate the effects of cytomegalovirus (CMV) DNA load on immune reconstitution and clinical outcomes of patients after unrelated cord blood transplantation (UCBT). METHODS:Eight-color flow cytometry was used to dynamically monitor the changes of peripheral blood lymphocyte subsets of 41 patients at one year after UCBT, and 10 healthy volunteers were enroled as controls. Patients were divided into two groups according to the DNA load of CMV (DNA copies <1000/ml and DNA copies ≥1000/ml). Comparative analyse of the effect of CMV DNA load on lymphocyte subsets and transplantation outcomes were carried out after transplantation. RESULTS:The high CMV DNA load group showed a faster and expanded T cell reconstitution, and the differences between the two groups were statistically significant at one and nine months after transplantation (0.38×10 /L vs 0.25×10 /L, P=0.015 and 2.53×10 /L vs 1.36×10 /L, P=0.006, respectively). Further analysis of T cell subsets suggested that CD8 T cells presented a higher and faster recovery in the high DNA load group, and the differences between the two groups were statistically significant at one and nine months after transplantation (0.20×10 /L vs 0.10×10 /L, P=0.038 and 1.62×10 /L vs 0.68×10 /L, P=0.003, respectively). In addition, there were no significant differences in levels of B cells, regulatory B cells and NK cells between the two groups. Outcomes after one- and a-half-year transplantation showed that there were no significant difference in relapse, non-relapse mortality and overall survival between the high and the low DNA load groups (7.7% vs 7.5%) (P=0.900) (15.4% vs 21.4%) (P=0.686) and (76.9% vs 78.6%) (P=0.889) respectively. CONCLUSION:The high CMV DNA load induces a faster and long-lasting expansion of T cells, mainly as the expansion of CD8 T cells after UCBT. Besides, under the current pre-emptive treatment of CMV, the high CMV DNA load does not affect the early survival of patients with acute myeloid leukemia after UCBT. 10.19746/j.cnki.issn.1009-2137.2019.05.043
    A comparative study of reduced dose alemtuzumab in matched unrelated donor and related donor reduced intensity transplants. Jardine Laura,Publicover Amy,Bigley Venetia,Hale Geoff,Pearce Kim,Dickinson Anne,Jackson Graham,Collin Matthew British journal of haematology In vivo T cell depletion with 100 mg alemtuzumab prevents graft-versus-host disease (GVHD) in reduced intensity conditioned transplants but is associated with delayed immune reconstitution, a higher risk of infection and relapse. De-escalation studies have shown that a reduced dose of 30 mg is as effective as 100 mg in preventing GVHD in matched related donor (MRD) transplants. Dose reduction in matched unrelated donor (MUD) transplants is feasible but the comparative efficacy of alemtuzumab in this setting is not known and opinions vary widely concerning the optimal level of GVHD prophylaxis that should be achieved. Through retrospective analysis we made an objective comparison of MUD transplants receiving an empirically reduced dose of 60 mg, with MRD transplants receiving a 30 mg dose. We observed proportionate levels of alemtuzumab according to dose but an inverse relationship with body surface area particularly in MRD transplants. MUD transplants experienced more acute and chronic GVHD, higher T cell chimerism, more sustained use of ciclosporin and less need for donor lymphocyte infusion than MRD transplants. Thus, doubling the dose of alemtuzumab to 60 mg did not provide equivalent prevention of GVHD after MUD transplant although there was no difference in non-relapse mortality or survival compared with MRD transplants. 10.1111/bjh.13239
    Reconstitution of lymphocyte subpopulations after hematopoietic stem cell transplantation: comparison of hematologic malignancies and donor types in event-free patients. Park Borae G,Park Chan-Jeoung,Jang Seongsoo,Chi Hyun-Sook,Kim Dae-Young,Lee Jung-Hee,Lee Je-Hwan,Lee Kyoo-Hyung Leukemia research The reconstitution of different immunocyte subsets after hematopoietic stem cell transplantation (HSCT), follows different timelines. We prospectively investigated changes in lymphocyte subsets after HSCT and their associations with primary diagnosis, conditioning regimen, and HSCT type in event-free patients. A total of 95 patients (48 with acute myeloid leukemia, 22 with acute lymphoid leukemia, and 25 with myelodysplastic syndrome) who underwent allogeneic HSCT (34 sibling matched, 37 unrelated matched, and 24 haploidentical HSCT) but did not experience any events such as relapse or death were enrolled in this study. Lymphocyte subpopulations (T cells, helper/inducer T cells, cytotoxic/suppressor T cells, memory T cells, regulatory T cells, natural killer (NK) cells, NK-T cells, and B cells) were quantified by flow cytometry of peripheral blood from recipients 7 days before and 1, 2, 3, 6, and 12 months after HSCT. Leukocyte counts recovered within 1 month after HSCT. However, the number of T and B lymphocytes recovered at 2 months after HSCT. NK cell counts recovered shortly after haploidentical HSCT. However, T lymphocytes and their subpopulations showed delayed recovery after haploidentical HSCT. Lymphocyte subsets showed different sequential patterns according to HSCT type but no differences were seen according to primary diagnosis or conditioning regimen. 10.1016/j.leukres.2015.09.010
    Rapid reconstitution of CD4 T cells and NK cells protects against CMV-reactivation after allogeneic stem cell transplantation. Drylewicz Julia,Schellens Ingrid M M,Gaiser Rogier,Nanlohy Nening M,Quakkelaar Esther D,Otten Henny,van Dorp Suzanne,Jacobi Ronald,Ran Leonie,Spijkers Sanne,Koning Dan,Schuurman Rob,Meijer Ellen,Pietersma Floortje L,Kuball Jurgen,van Baarle Debbie Journal of translational medicine BACKGROUND:Epstein-Barr virus and Cytomegalovirus reactivations frequently occur after allogeneic stem cell transplantation (SCT). METHODS:Here we investigated the role of immune cell reconstitution in the onset and subsequent severity of EBV- and CMV-reactivation. To this end, 116 patients were prospectively sampled for absolute T cell (CD4 and CD8), B-cell (CD19) and NK-cell (CD16 and CD56) numbers weekly post-SCT during the first 3 months and thereafter monthly until 6 months post-SCT. Viral load was monitored in parallel. RESULTS:In contrast to the general belief, we found that early T-cell reconstitution does not play a role in the onset of viral reactivation. CMV reactivation in the first 7 weeks after SCT however resulted in higher absolute CD8(+) T-cell numbers 6 months post-SCT in patients with high-level reactivation, many of which were CMV-specific. Interestingly, rapid reconstitution of CD4(+) T-cells, as well as NK cells and the presence of donor KIR3DL1, are associated with the absence of CMV-reactivation after SCT, suggestive of a protective role of these cells. In contrast, EBV-reactivations were not affected in any way by the level of immune reconstitution after SCT. CONCLUSION:In conclusion, these data suggest that CD4(+) T-cells and NK cells, rather than CD8(+) T-cells, are associated with protection against CMV-reactivation. 10.1186/s12967-016-0988-4
    Excellent T-cell reconstitution and survival depend on low ATG exposure after pediatric cord blood transplantation. Admiraal Rick,Lindemans Caroline A,van Kesteren Charlotte,Bierings Marc B,Versluijs A Birgitta,Nierkens Stefan,Boelens Jaap Jan Blood Successful immune reconstitution (IR) is associated with improved outcomes following pediatric cord blood transplantation (CBT). Usage and timing of anti-thymocyte globulin (ATG), introduced to the conditioning to prevent graft-versus-host disease and graft failure, negatively influences T-cell IR. We studied the relationships among ATG exposure, IR, and clinical outcomes. All pediatric patients receiving a first CBT between 2004 and 2015 at the University Medical Center Utrecht were included. ATG-exposure measures were determined with a validated pharmacokinetics model. Main outcome of interest was early CD4 IR, defined as CD4 T-cell counts >50 × 10/L twice within 100 days after CBT. Other outcomes of interest included event-free survival (EFS). Cox proportional-hazard and Fine-Gray competing-risk models were used. A total of 137 patients, with a median age of 7.4 years (range, 0.2-22.7), were included, of whom 82% received ATG. Area under the curve (AUC) of ATG after infusion of the cord blood transplant predicted successful CD4 IR. Adjusted probability on CD4 IR was reduced by 26% for every 10-point increase in AUC after CBT (hazard ratio [HR], 0.974; P < .0001). The chance of EFS was higher in patients with successful CD4 IR (HR, 0.26; P < .0001) and lower ATG exposure after CBT (HR, 1.005; P = .0071). This study stresses the importance of early CD4 IR after CBT, which can be achieved by reducing the exposure to ATG after CBT. Individualized dosing of ATG to reach optimal exposure or, in selected patients, omission of ATG may contribute to improved outcomes in pediatric CBT. 10.1182/blood-2016-06-721936
    Tracking T-cell immune reconstitution after TCRαβ/CD19-depleted hematopoietic cells transplantation in children. Zvyagin I V,Mamedov I Z,Tatarinova O V,Komech E A,Kurnikova E E,Boyakova E V,Brilliantova V,Shelikhova L N,Balashov D N,Shugay M,Sycheva A L,Kasatskaya S A,Lebedev Y B,Maschan A A,Maschan M A,Chudakov D M Leukemia αβT-cell-depleted allogeneic hematopoietic cell transplantation holds promise for the safe and accessible therapy of both malignant and non-malignant blood disorders. Here we employed molecular barcoding normalized T-cell receptor (TCR) profiling to quantitatively track T-cell immune reconstitution after TCRαβ-/CD19-depleted transplantation in children. We demonstrate that seemingly early reconstitution of αβT-cell counts 2 months after transplantation is based on only several hundred rapidly expanded clones originating from non-depleted graft cells. In further months, frequency of these hyperexpanded clones declines, and after 1 year the observed T-cell counts and TCRβ diversity are mostly provided by the newly produced T cells. We also demonstrate that high TCRβ diversity at day 60 observed for some of the patients is determined by recipient T cells and intrathymic progenitors that survived conditioning regimen. Our results indicate that further efforts on optimization of TCRαβ-/CD19-depleted transplantation protocols should be directed toward providing more efficient T-cell defense in the first months after transplantation. 10.1038/leu.2016.321
    CD25 Blockade Delays Regulatory T Cell Reconstitution and Does Not Prevent Graft-versus-Host Disease After Allogeneic Hematopoietic Cell Transplantation. Locke Frederick L,Pidala Joseph,Storer Barry,Martin Paul J,Pulsipher Michael A,Chauncey Thomas R,Jacobsen Niels,Kröger Nicolaus,Walker Irwin,Light Susan,Shaw Bronwen E,Beato Francisca,Laport Ginna G,Nademanee Auayporn,Keating Armand,Socie Gerard,Anasetti Claudio Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Daclizumab, a humanized monoclonal antibody, binds CD25 and blocks formation of the IL-2 receptor on T cells. A study of daclizumab as acute graft-versus-host disease (GVHD) prophylaxis after unrelated bone marrow transplantation was conducted before the importance of CD25FOXP3 regulatory T cells (Tregs) was recognized. Tregs can abrogate the onset of GVHD. The relation between Tregs and a graft-versus-malignancy effect is not fully understood. An international, multicenter, double-blind clinical trial randomized 210 adult or pediatric patients to receive 5 weekly doses of daclizumab at 0.3 mg/kg (n = 69) or 1.2 mg/kg (n = 76) or placebo (n = 65) after unrelated marrow transplantation for treatment of hematologic malignancies or severe aplastic anemia. The risk of acute GVHD did not differ among the groups (P = .68). Long-term follow-up of clinical outcomes and correlative analysis of peripheral blood T cell phenotype suggested that the patients treated with daclizumab had an increased risk of chronic GVHD (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.0 to 2.3; P = .08) and a decreased risk of relapse (HR, 0.57; 95% CI, 0.3 to 1.0; P = .05), but similar survival (HR, 0.89; 95% CI, 0.6 to 1.3; P = .53). T cells from a subset of patients (n = 107) were analyzed by flow cytometry. Compared with placebo, treatment with daclizumab decreased the proportion of Tregs among CD4 T cells at days 11-35 and increased the proportion of central memory cells among CD4 T cells at 1 year. Prophylactic administration of daclizumab does not prevent acute GVHD, but may increase the risk of chronic GVHD and decrease the risk of relapse. By delaying Treg reconstitution and promoting immunologic memory, anti-CD25 therapy may augment alloreactivity and antitumor immunity. 10.1016/j.bbmt.2016.12.624
    Reconstitution of immune cell populations in multiple sclerosis patients after autologous stem cell transplantation. Karnell F G,Lin D,Motley S,Duhen T,Lim N,Campbell D J,Turka L A,Maecker H T,Harris K M Clinical and experimental immunology Multiple sclerosis is an inflammatory T cell-mediated autoimmune disease. In a Phase II clinical trial, high-dose immunosuppressive therapy combined with autologous CD34 haematopoietic stem cell transplant resulted in 69·2% of subjects remaining disease-free without evidence of relapse, loss of neurological function or new magnetic resonance imaging (MRI) lesions to year 5 post-treatment. A combination of CyTOF mass cytometry and multi-parameter flow cytometry was used to explore the reconstitution kinetics of immune cell subsets in the periphery post-haematopoietic cell transplant (HSCT) and the impact of treatment on the phenotype of circulating T cells in this study population. Repopulation of immune cell subsets progressed similarly for all patients studied 2 years post-therapy, regardless of clinical outcome. At month 2, monocytes and natural killer (NK) cells were proportionally more abundant, while CD4 T cells and B cells were reduced, relative to baseline. In contrast to the changes observed at earlier time-points in the T cell compartment, B cells were proportionally more abundant and expansion in the proportion of naive B cells was observed 1 and 2 years post-therapy. Within the T cell compartment, the proportion of effector memory and late effector subsets of CD4 and CD8 T cells was increased, together with transient increases in proportions of CD45RA-regulatory T cells (T ) and T helper type 1 (Th1 cells) and a decrease in Th17·1 cells. While none of the treatment effects studied correlated with clinical outcome, patients who remained healthy throughout the 5-year study had significantly higher absolute numbers of memory CD4 and CD8 T cells in the periphery prior to stem cell transplantation. 10.1111/cei.12985
    Combined OX40L and mTOR blockade controls effector T cell activation while preserving T reconstitution after transplant. Tkachev Victor,Furlan Scott N,Watkins Benjamin,Hunt Daniel J,Zheng Hengqi Betty,Panoskaltsis-Mortari Angela,Betz Kayla,Brown Melanie,Schell John B,Zeleski Katie,Yu Alison,Kirby Ian,Cooley Sarah,Miller Jeffrey S,Blazar Bruce R,Casson Duncan,Bland-Ward Phil,Kean Leslie S Science translational medicine A critical question facing the field of transplantation is how to control effector T cell (T) activation while preserving regulatory T cell (T) function. Standard calcineurin inhibitor-based strategies can partially control T, but breakthrough activation still occurs, and these agents are antagonistic to T function. Conversely, mechanistic target of rapamycin (mTOR) inhibition with sirolimus is more T-compatible but is inadequate to fully control T activation. In contrast, blockade of OX40L signaling has the capacity to partially control T activation despite maintaining T function. We used the nonhuman primate graft-versus-host disease (GVHD) model to probe the efficacy of combinatorial immunomodulation with sirolimus and the OX40L-blocking antibody KY1005. Our results demonstrate significant biologic activity of KY1005 alone (prolonging median GVHD-free survival from 8 to 19.5 days), as well as marked, synergistic control of GVHD with KY1005 + sirolimus (median survival time, >100 days; < 0.01 compared to all other regimens), which was associated with potent control of both T/T1 (T helper cell 1/cytotoxic T cell 1) and T/T17 activation. Combined administration also maintained T reconstitution [resulting in an enhanced T/T ratio (40% over baseline) in the KY1005/sirolimus cohort compared to a 2.9-fold decrease in the unprophylaxed GVHD cohort]. This unique immunologic signature resulted in transplant recipients that were able to control GVHD for the length of analysis and to down-regulate donor/recipient alloreactivity despite maintaining anti-third-party responses. These data indicate that combined OX40L blockade and sirolimus represents a promising strategy to induce immune balance after transplant and is an important candidate regimen for clinical translation. 10.1126/scitranslmed.aan3085
    The influence of lymphoid reconstitution kinetics on clinical outcomes in allogeneic stem cell transplantation. Kobulnicky David J,Sabo Roy T,Sharma Shashank,Shubar Ali Ali S,Kobulnicky Kristen M,Roberts Catherine H,Clark William B,Chung Harold M,McCarty John M,Toor Amir A Leukemia & lymphoma Lymphoid recovery following myeloablative stem cell transplantation (SCT) displays a logistic pattern of exponential growth followed by a plateau. Within this logistic framework, lymphoid recovery is characterized by the parameters R (slope of ascent), a (time of maximal rate of ascent) and K (plateau), the 'steady-state' lymphocyte count. A retrospective analysis of allogeneic SCT performed from 2008 to 2013 was undertaken to compare lymphoid recovery and clinical outcomes in 131 patients with acute myelogenous leukemia, acute lymphocytic leukemia, and myelodysplastic syndromes. Using Prism software, a logistic curve was successfully fit to the absolute lymphocyte count recovery in all patients. Patients were classified according to the magnitude and rate of lymphoid recovery; pattern A achieved an absolute lymphocyte counts (ALC) of >1000/μL by day 45, pattern B an ALC 500 < x < 1000/μL, and pattern C an ALC <500/μL. Pattern A was characterized by a higher mean K (p < .0001) compared with patterns B and C. Patients with patterns B and C were more likely to have mixed T cell chimerism at 90 d following SCT (p = .01). There was a trend towards improved survival (and relapse-free survival) in those with pattern A and B at 1 year compared to pattern C (p = .073). There was no difference in cGVHD (p = .42) or relapse (p = .45) between pattern types. Cytomegalovirus (CMV), aGVHD, and all relapse were heralded by deviation from logistic behavior. Pattern C patients were more likely to require donor lymphocyte infusion (DLI) (p = .017). Weaning of tacrolimus post-transplant was associated with a second, separate logistic expansion in some patients. This study demonstrated that lymphoid reconstitution follows a prototypical logistic recovery and that pattern observed correlates with T cell chimerism and need for DLI, and may influence survival. 10.1080/10428194.2018.1452216
    Dynamics of Lymphocyte Reconstitution After Hematopoietic Transplantation During Chronic Lymphocytic Choriomeningitis Virus Infection. Bhattacharyya Mitra,Penaloza-MacMaster Pablo AIDS research and human retroviruses Bone marrow transplantation is a treatment for various cancers and genetic diseases, and the only case of a cured HIV infection involved the use of this clinical procedure, highlighting the potential use of this therapy for curing many chronic diseases. However, little is known about how chronic viral infection influences lymphocyte reconstitution after bone marrow transplantation. To address this, we infected mice with chronic lymphocytic choriomeningitis virus, and performed bone marrow transplantation to assess lymphocyte reconstitution. Interestingly, we observed that adoptively transferred marrow cells exhibited preferential B cell differentiation in chronically infected mice. Moreover, donor marrow cells that were adoptively transferred into chronically infected mice differentiated into virus-specific CD8 T cells that were able to expand after PD-L1 blockade. Taken together, our data show that chronic viral infection induces a biased differentiation of bone marrow stem cells into B cells, and that exhausted virus-specific CD8 T cells generated de novo in this setting are rescuable by PD-1 blockade. These data contribute to the understanding of how chronic viral infection impacts lymphocyte reconstitution, and may provide valuable information to improve current hematopoietic transplantation regimens in chronically infected hosts. 10.1089/AID.2017.0251
    Immune reconstitution of HLA-A*0201/BMLF1- and HLA-A*1101/LMP2-specific Epstein Barr virus cytotoxic T lymphocytes within 90 days after haploidentical hematopoietic stem cell transplantation. Zhou Ling,Lu Dao-Pei Virology journal BACKGROUND:Haploidentical hematopoietic stem cell transplant (haplo-HSCT) recipients are at high risk for Epstein Barr virus (EBV)-related diseases. EBV-specific CD8 cytotoxic T cells can control EBV-infected B cell expansion; however, no studies have investigated EBV-specific immune reconstitution after HSCT, particularly haplo-HSCT. Therefore, in this study, we aimed to characterize EBV-specific immune cell reconstitution after haplo-HSCT. METHODS:HLA-A*1101 and HLA-A*0201 pentamers folded with immunodominant EBV peptides were used to detect EBV-specific CD8 T cells by flow cytometry in peripheral blood mononuclear cells from 19 haplo-HSCT recipients and the results were compared with those in controls. We also compared the EBV-specific pentamer-binding cell frequencies in patients with or without EBV-related diseases by flow cytometry. RESULTS:Pentamer-binding EBV-specific CD8 T cells were detected at + 30, + 60 and + 90 days after haplo-HSCT in EBV-seropositive patients subjected to haplo-HSCT from an EBV-seropositive donor. The frequencies of the HLA-A*0201/BMLF1-GLC pentamer in haplo-HSCT patients at + 30 days were significantly lower than those in HLA-A*0201-positive healthy controls (p = 0.019) and patients at + 60 days (p = 0.003). The frequencies of the HLA-A*1101/LMP2-SSC pentamer at + 30, + 60, and + 90 days were significantly decreased compared with those in healthy controls (p = 0.009, 0.019, and 0.039, respectively); however, the frequencies of the HLA-A*1101/LMP2-SSC pentamer did not differ significantly among patients at + 30, + 60, and + 90 days (p = 0.886). There was a significant difference in the frequency of the HLA-A*0201/BMLF1-GLC pentamer at + 60 days between patients with and without EBV-related diseases (p = 0.024). Patients with EBV-related diseases showed lower percentages of HLA-A*0201/BMLF1-GLC specific CD8 T cells. CONCLUSIONS:Haplo-HSCT recipients could generate EBV-specific CD8 T cells within + 30 days after transplantation. The HLA-A*0201/BMLF1-GLC pentamer cell frequency at + 60 days may be a useful indicator for monitoring EBV-related diseases in patients after haplo-HSCT. Transfusion with EBV-CTLs within 60 days after haplo-HSCT may have prophylactic effects against EBV-related diseases. 10.1186/s12985-019-1123-y
    Differences of Immune Reconstitution of Dendritic Cells in Pediatric GvHD Patients After Allogenic Stem Cell Transplantation. Wiegering Verena,Peter Lisa,Frietsch Marieke,Schlegel Paul G,Eyrich Matthias Journal of pediatric hematology/oncology BACKGROUND:Hematopoietic stem cell transplantation (HSCT) is a life-saving procedure for children with a variety of (non) malignant conditions. GvHD is a severe complication with high morbidity and mortality. The pathogenesis remains unclear. We studied dendritic cell (DC) reconstitution to detect potential differences, which may improve our knowledge in the development of chronic GvHD (cGvHD). PROCEDURE:We examined immune reconstitution (T, B, and NK cells and dendritic cells) at defined time points in a pediatric cohort who underwent 61 allogeneic HSCTs. RESULTS:Regarding DC reconstitution we found a fast reconstitution of the DC compartment negatively correlated with age. After HSCT, both myeloid DC (mDC) and plasmacytoid DC (pDC) counts recover to pre-HSCT levels within 2 months. Higher CCR7 positive cell counts were found in patients receiving TBI during engraftment and during the whole posttransplant period we found a correlation with an improved outcome. In cGVHD patients decreased total DC counts and increased pDCs were found after day+100. No relevant correlation was achieved regarding to HLA-matching, stem cell manipulation of the graft as well as HSCT-indication compared with different DC counts. DISCUSSION:Pathogenesis of cGvHD remains complex. Our data suggest an influence of dendritic cells, which may contribute to the clinical picture and should be further investigated in future studies. 10.1097/MPH.0000000000001342
    Reactivation of BK virus after double umbilical cord blood transplantation in adults correlates with impaired reconstitution of CD4 and CD8 T effector memory cells and increase of T regulatory cells. Karantanos Theodoros,Kim Haesook T,Tijaro-Ovalle Natalia M,Li Lequn,Cutler Corey,Antin Joseph H,Ballen Karen,Marty Francisco M,Tan Chen Sabrina,Ritz Jerome,Politikos Ioannis,Boussiotis Vassiliki Clinical immunology (Orlando, Fla.) BK virus (BKV), a human polyomavirus that remains latent in renal epithelial cells, can be reactivated after hematopoietic stem cell transplantation (HSCT) leading to hemorrhagic cystitis. The incidence of BK viremia is higher after Umbilical cord blood transplantation (UCBT) than HSCT from adult donors. Data regarding the role of immune recovery after UCBT in BKV reactivation is lacking. We examined the correlation between the development of BK viremia and immune reconstitution in 27 adult recipients of UCBT. The incidence of BK viremia was 52% and developed most frequently within the first 8 weeks after the transplantation, but persisted in seven patients at 6 months, and three patients at 1-year post UCBT. Detection of BK viremia 1 year after transplant was negatively associated with the number of CD8 cells (p = 0.03) and CD8CD45RO cells (p = 0.05) at 6 months, and the number of CD4 (p = 0.03) and CD4CD45RO cells (p = 0.03) at 12 months after UCBT. Conversely, BK viremia at 6 and 12 months was positively correlated with the number of T regulatory (Treg) cells at 1 month (p = 0.005 and p = 0.016, respectively). Because UCB Treg have highly potent immunosuppressive function, our findings indicate that sustained BK viremia in UCBT recipients might be associated with the increase of Treg cells early after transplantation, which mediate impaired and delayed reconstitution of CD4 and CD8 T effector cells. 10.1016/j.clim.2019.06.010
    B-cell reconstitution recapitulates B-cell lymphopoiesis following haploidentical BM transplantation and post-transplant CY. Roberto A,Castagna L,Gandolfi S,Zanon V,Bramanti S,Sarina B,Crocchiolo R,Todisco E,Carlo-Stella C,Tentorio P,Timofeeva I,Santoro A,Della Bella S,Roederer M,Mavilio D,Lugli E Bone marrow transplantation 10.1038/bmt.2014.266
    Dynamical System Modeling of Immune Reconstitution after Allogeneic Stem Cell Transplantation Identifies Patients at Risk for Adverse Outcomes. Toor Amir A,Sabo Roy T,Roberts Catherine H,Moore Bonny L,Salman Salman R,Scalora Allison F,Aziz May T,Shubar Ali Ali S,Hall Charles E,Meier Jeremy,Thorn Radhika M,Wang Elaine,Song Shiyu,Miller Kristin,Rizzo Kathryn,Clark William B,McCarty John M,Chung Harold M,Manjili Masoud H,Neale Michael C Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Systems that evolve over time and follow mathematical laws as they evolve are called dynamical systems. Lymphocyte recovery and clinical outcomes in 41 allograft recipients conditioned using antithymocyte globulin (ATG) and 4.5-Gy total body irradiation were studied to determine if immune reconstitution could be described as a dynamical system. Survival, relapse, and graft-versus-host disease (GVHD) were not significantly different in 2 cohorts of patients receiving different doses of ATG. However, donor-derived CD3(+) cell reconstitution was superior in the lower ATG dose cohort, and there were fewer instances of donor lymphocyte infusion (DLI). Lymphoid recovery was plotted in each individual over time and demonstrated 1 of 3 sigmoid growth patterns: Pattern A (n = 15) had rapid growth with high lymphocyte counts, pattern B (n = 14) had slower growth with intermediate recovery, and pattern C (n = 10) had poor lymphocyte reconstitution. There was a significant association between lymphocyte recovery patterns and both the rate of change of donor-derived CD3(+) at day 30 after stem cell transplantation (SCT) and clinical outcomes. GVHD was observed more frequently with pattern A, relapse and DLI more so with pattern C, with a consequent survival advantage in patients with patterns A and B. We conclude that evaluating immune reconstitution after SCT as a dynamical system may differentiate patients at risk of adverse outcomes and allow early intervention to modulate that risk. 10.1016/j.bbmt.2015.03.011
    Immune reconstitution after cord blood transplantation: peculiarities, clinical implications and management strategies. Lucchini Giovanna,Perales Miguel-Angel,Veys Paul Cytotherapy Umbilical cord blood (UCB) is now widely used as an alternative hematopoietic stem cell source for patients lacking closely matched related or unrelated adult donors. UCB transplantation has traditionally been associated with delayed engraftment, poor immune reconstitution and consequent increased risk of infection. More recent clinical studies, however, suggest that conditioning regimens and in particular the omission of in vivo T-cell depletion may play a crucial role in post-transplant T-cell expansion, facilitating a uniquely rapid immune recovery after UCB transplantation. The peculiar characteristics of UCB cells, the importance of thymic function and the role of conditioning regimens and graft-versus-host disease influencing immune reconstitution are described. The last part of the review reports available data on UCB, as well as third-party peripheral blood derived anti-viral cell therapy, which provides a novel approach to rescue UCB recipients with viral complications in the post-transplant period. 10.1016/j.jcyt.2015.03.614
    Immune Reconstitution after Allogeneic Hematopoietic Cell Transplantation in Children. de Koning Coco,Plantinga Maud,Besseling Paul,Boelens Jaap Jan,Nierkens Stefan Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Allogeneic (allo) hematopoietic cell transplantation (HCT) has evolved into a potent curative treatment option for a variety of malignant and nonmalignant diseases. The occurrence of complications and mortality after allo-HCT is, however, still high and is strongly associated with immune reconstitution (IR). Therefore, detailed information on IR through immunomonitoring is crucial to improve survival chances after HCT. To date, information about the reconstituting immune system after allo-HCT in pediatric patients is mostly derived from routine standard-of-care measurements. More profound knowledge on IR may provide tools to better predict and modulate adverse reactions and, subsequently, improve survival chances. Here, we provide an overview of IR (eg, immune cell subsets and circulating chemokines/cytokines) after allo-HCT in children, taking into account different cell sources and serotherapy, and discuss strategies to enhance immunomonitoring. We conclude that available IR data after allo-HCT contain limited information on immune cell families (mostly only generic T, B, and NK cells), which would improve with more detailed information on reconstituting cell subsets or effector cell functionality at earlier time points (<1 month). In addition, secretome data (eg, multiplex cytokine/chemokine profiles) could add to the understanding of IR mechanisms and cell functionality and may even provide (early) biomarkers for individual disease outcome, such as viral reactivity, graft-versus-host disease, or graft-versus-leukemia. The present data and suggestions for more detailed, standardized, and harmonized immunomonitoring in future (pediatric) allo-HCT studies will pave the path to "precision transplantation:" an individualized HCT approach (including conditioning), based on detailed information on IR and biomarkers, aiming to reduce transplantation related mortality and relapse, and subsequently improve survival chances. 10.1016/j.bbmt.2015.08.028
    Immune Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation. Ogonek Justyna,Kralj Juric Mateja,Ghimire Sakhila,Varanasi Pavankumar Reddy,Holler Ernst,Greinix Hildegard,Weissinger Eva Frontiers in immunology The timely reconstitution and regain of function of a donor-derived immune system is of utmost importance for the recovery and long-term survival of patients after allogeneic hematopoietic stem cell transplantation (HSCT). Of note, new developments such as umbilical cord blood or haploidentical grafts were associated with prolonged immunodeficiency due to delayed immune reconstitution, raising the need for better understanding and enhancing the process of immune reconstitution and finding strategies to further optimize these transplant procedures. Immune reconstitution post-HSCT occurs in several phases, innate immunity being the first to regain function. The slow T cell reconstitution is regarded as primarily responsible for deleterious infections with latent viruses or fungi, occurrence of graft-versus-host disease, and relapse. Here we aim to summarize the major steps of the adaptive immune reconstitution and will discuss the importance of immune balance in patients after HSCT. 10.3389/fimmu.2016.00507
    Increasing Stem Cell Dose Promotes Posttransplant Immune Reconstitution. Xu Ning,Shen Sylvie,Dolnikov Alla Stem cells and development Umbilical cord blood (UCB) transplantation can provide a successful therapeutic option for patients that have no suitable related donor. UCB transplantation is often limited by the relatively small hematopoietic stem cell (HSC) numbers in UCB especially for adult recipients. Early neutrophil and platelet engraftment correlates with the stem cell numbers in UCB transplant. Compared to other HSC sources, immune reconstitution following UCB transplant is slower and complicated by increased frequency of opportunistic infections. The effect of HSC numbers in UCB transplant on immune reconstitution was not thoroughly examined. Using immunocompromised mice transplanted with purified UCB CD34+ stem cells, we have demonstrated that increasing the numbers of CD34+ cells in the transplant promotes hematopoietic and immune reconstitution. At early stages posttransplant, high stem cell dose generated relatively more B cells, while lower dose generated more myeloid and T cells. Thus, the size of the stem cell graft appears to modulate the differentiation potential of infused stem cells. In addition, increasing stem cell dose in the transplant improved CD8+ T cell development and delayed late memory T cell skewing in expense of naive T cells highlighting the importance of HSC dose to maintain the pool of naive T cells able to develop strong immune responses. Transplantation of ex vivo expanded CD34+ cells did not promote, but rather delayed immune reconstitution suggesting the loss of primitive lymphoid precursor cells during ex vivo expansion. 10.1089/scd.2016.0186
    Long-term immune reconstitution and T cell repertoire analysis after autologous hematopoietic stem cell transplantation in systemic sclerosis patients. Farge Dominique,Arruda Lucas C M,Brigant Fanny,Clave Emmanuel,Douay Corinne,Marjanovic Zora,Deligny Christophe,Maki Guitta,Gluckman Eliane,Toubert Antoine,Moins-Teisserenc Helene Journal of hematology & oncology The determinants of clinical responses after autologous hematopoietic stem cell transplantation (aHSCT) in systemic sclerosis (SSc) are still unraveled. We analyzed long-term immune reconstitution (IR) and T cell receptor (TCR) repertoire diversity in 10 SSc patients, with at least 6 years simultaneous clinical and immunological follow-up after aHSCT. Patients were retrospectively classified as long-term responders (A, n = 5) or non-responders (B, n = 5), using modified Rodnan's skin score (mRSS) and forced vital capacity (FVC%). All patients had similar severe SSc before aHSCT. Number of reinjected CD34 cells was higher in group B versus A (P = 0.02). Long-term mRSS fall >25% was more pronounced in group A (P = 0.004), the only to improve long-term FVC% >10% (P = 0.026). There was an overall trend toward increased of T cell reconstitution in group B versus A. B cells had a positive linear regression slope in group A (LRS = 11.1) and negative in group B (LRS = -11.6). TCR repertoire was disturbed before aHSCT and the percentage of polyclonal families significantly increased at long-term (P = 0.046), with no difference between groups. Despite improved skin score after aHSCT in all SSc patients, pretransplant B cell clonal expansion and faster post-transplant T cell IR in long-term non-responder/relapsing patients call for new therapeutic protocols guided by IR analysis to improve their outcome. 10.1186/s13045-016-0388-5
    Impact of stem cell graft on early viral infections and immune reconstitution after allogeneic transplantation in adults. Illiaquer Marina,Imbert-Marcille Berthe-Marie,Guillaume Thierry,Planche Lucie,Rimbert Marie,Bressollette-Bodin Céline,Le Bourgeois Amandine,Peterlin Pierre,Garnier Alice,Le Houerou Claire,Moreau Philippe,Mohty Mohamad,Chevallier Patrice Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology BACKGROUND:Viral infections are well-known complications after allogeneic stem cell transplant (allo-SCT). OBJECTIVES:We compared prospectively incidences of DNAemia and active infections (AI) for five opportunistic viruses (Human Herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV), BK polyomavirus (BKPyV), Cytomegalovirus (CMV) and Adenovirus (ADV)) and kinetics of immune reconstitution (IR) in adults receiving either double umbilical cord blood (dUCB group) or unrelated peripheral blood stem cell (uPBSC group) allo-SCT after a reduced-intensity conditioning (RIC) regimen. STUDY DESIGN:Whole blood samples were collected at transplant, every 15days during the first 3 months and at 4, 5 and 6 months post-transplant. RESULTS:Sixty-five patients were enrolled (uPBSC n=34; dUCB n=31). Incidences of HHV-6 and BKPyV DNAemia were significantly higher for dUCB (97% vs 23.5% and 58% vs 32%, respectively) while EBV DNAemia was more frequently detected in uPBSC (71% vs 26%). The incidence of CMV DNAemia was similar between both groups. ADV AI developed only in dUCB. HHV-6 AI were also higher in dUCB (84% vs 21%). In multivariate analysis, dUCB graft was the only independent factor associated with HHV-6 DNAemia (OR: 19.0; 95%CI: 5.2-69.1; p<0.0001) while EBV DNAemia were significantly associated with uPBSC (OR: 29.9; 95%CI: 5.68-158; p <0.0001). dUCB graft was also the only factor associated with HHV-6 AI. Finally, higher counts and faster recoveries of B lymphocytes (p<0.0001) and monocytes (p=0.0007) were observed in the dUCB group. CONCLUSION:We demonstrate a strong correlation between sources of graft and patterns of viral DNAemia and AI and IR after RIC allo-SCT. 10.1016/j.jcv.2017.05.019
    Assessing the risk of CMV reactivation and reconstitution of antiviral immune response post bone marrow transplantation by the QuantiFERON-CMV-assay and real time PCR. Krawczyk Adalbert,Ackermann Jessica,Goitowski Birgit,Trenschel Rudolf,Ditschkowski Markus,Timm Jörg,Ottinger Hellmut,Beelen Dietrich W,Grüner Nico,Fiedler Melanie Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology BACKGROUND:CMV reactivation is a major cause of severe complications in allogeneic hematopoietic stem cell transplant (HSCT) recipients. The risk of CMV reactivation depends on the serostatus (+/-) of the donor (D) and recipient (R). The reconstitution of CMV-specific T-cell responses after transplantation is crucial for the control of CMV reactivation. OBJECTIVES:The study aimed to determine the cellular immune status correlating with protection from high-level CMV viremia (>5000 copies/ml) and disease. STUDY DESIGN:We monitored CMV-specific cellular immune responses in 9 high-risk (D-/R+), 14 intermediate risk (D+/R+) and 3 low risk individuals (D+/R-), and 8 CMV negative controls (D-/R-). Interferon- γ (IFN-γ) levels as a marker for the CD8+ T-cell response were determined by the QuantiFERON-CMV-assay and compared to viral loads determined by PCR. RESULTS:Early CMV reactivation was detected in all high-risk and 13/14 intermediate risk individuals. High-level viremia was detected in 5/7 high and 7/14 intermediate risk patients. Reconstitution of the CMV-specific cellular immune response started from 3 months after transplantation and resulted in protection against CMV reactivation. Re-establishing of CMV-specific T-cell immune responses with IFN- γ levels >8.9 IU/ml is crucial for protection from high-level CMV viremia. CONCLUSIONS:Monitoring of HSCT-recipients with the QuantiFERON-CMV-assay might be of great benefit to optimize antiviral treatment. 10.1016/j.jcv.2018.01.002
    Circulating monocyte subsets in multiple myeloma patients receiving autologous stem cell transplantation - a study of the preconditioning status and the course until posttransplant reconstitution for a consecutive group of patients. Rundgren Ida Marie,Ersvær Elisabeth,Ahmed Aymen Bushra,Ryningen Anita,Bruserud Øystein BMC immunology BACKGROUND:Induction therapy of multiple myeloma patients prior to autologous stem cell transplantation has changed from conventional chemotherapy to treatment based on proteasome inhibitors or immunomodulatory drugs. We used flow cytometry to analyze total monocyte and monocyte subset (classical, intermediate and non-classical monocytes) peripheral blood levels before and following auto-transplantation for a consecutive group of myeloma patients who had received the presently used induction therapy. RESULTS:The patients showed normal total monocyte concentrations after induction/stem cell mobilization, but the concentrations of classical monocytes were increased compared with healthy controls. Melphalan conditioning reduced the levels of total CD14 as well as classical and non-classical monocytes, whereas intermediate monocytes were not affected. Thus, melphalan has a non-random effect on monocyte subsets. Melphalan had a stronger effect on total and classical monocyte concentrations for those patients who had received induction therapy including immunomodulatory drugs. Total monocytes and monocyte subset concentrations decreased during the period of pancytopenia, but monocyte reconstitution occurred before hematopoietic reconstitution. However, the fractions of various monocyte subsets varied considerably between patients. CONCLUSIONS:The total level of circulating monocytes is normalized early after auto-transplantation for multiple myeloma, but pre- and post-transplant levels of various monocyte subsets show considerable variation between patients. 10.1186/s12865-019-0323-y
    Immune reconstitution in patients with acquired severe aplastic anemia after haploidentical stem cell transplantation. Pei X-Y,Zhao X-Y,Xu L-P,Wang Y,Zhang X-H,Chang Y-J,Huang X-J Bone marrow transplantation Immune recovery (IR) after haploidentical stem cell transplantation (haplo-SCT) in severe aplastic anemia (SAA) patients remains relatively unknown. In this study, we examined immune cell subset counts and immunoglobulins in 81 SAA patients from day 30 to day 365 after haplo-SCT. Simultaneously, we determined which factors influence IR and analyzed the effects of immune cell subsets on transplant outcomes. We found that: (i) The reconstitution of different immune cell subsets occurred at different rates after haplo-SCT. Monocytes were the first to recover, followed by CD8 T and CD19 B cells, and finally CD4 T cells. (ii) In the multivariate analysis, lower recipient age, female gender, high mononuclear cell counts in the graft and absence of CMV reactivation were associated with improved IR after transplant. (iii) A CD4/CD8 ratio less than 0.567 on day 30 post transplantation was associated with higher overall survival after haplo-SCT in SAA patients. In conclusion, SAA patients showed a faster recovery of monocytes and CD8 T cells after haplo-SCT, whereas the recovery of the CD4 T-cell subset was delayed. Our results may provide insight into methods for better predicting and modulating IR of SAA patients and subsequently improving outcomes after transplantation. 10.1038/bmt.2017.174
    Immune reconstitution and survival of 100 SCID patients post-hematopoietic cell transplant: a PIDTC natural history study. Heimall Jennifer,Logan Brent R,Cowan Morton J,Notarangelo Luigi D,Griffith Linda M,Puck Jennifer M,Kohn Donald B,Pulsipher Michael A,Parikh Suhag,Martinez Caridad,Kapoor Neena,O'Reilly Richard,Boyer Michael,Pai Sung-Yun,Goldman Frederick,Burroughs Lauri,Chandra Sharat,Kletzel Morris,Thakar Monica,Connelly James,Cuvelier Geoff,Davila Saldana Blachy J,Shereck Evan,Knutsen Alan,Sullivan Kathleen E,DeSantes Kenneth,Gillio Alfred,Haddad Elie,Petrovic Aleksandra,Quigg Troy,Smith Angela R,Stenger Elizabeth,Yin Ziyan,Shearer William T,Fleisher Thomas,Buckley Rebecca H,Dvorak Christopher C Blood The Primary Immune Deficiency Treatment Consortium (PIDTC) is enrolling children with severe combined immunodeficiency (SCID) to a prospective natural history study. We analyzed patients treated with allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2014, including 68 patients with typical SCID and 32 with leaky SCID, Omenn syndrome, or reticular dysgenesis. Most (59%) patients were diagnosed by newborn screening or family history. The 2-year overall survival was 90%, but was 95% for those who were infection-free at HCT vs 81% for those with active infection ( = .009). Other factors, including the diagnosis of typical vs leaky SCID/Omenn syndrome, diagnosis via family history or newborn screening, use of preparative chemotherapy, or the type of donor used, did not impact survival. Although 1-year post-HCT median CD4 counts and freedom from IV immunoglobulin were improved after the use of preparative chemotherapy, other immunologic reconstitution parameters were not affected, and the potential for late sequelae in extremely young infants requires additional evaluation. After a T-cell-replete graft, landmark analysis at day +100 post-HCT revealed that CD3 < 300 cells/μL, CD8 < 50 cells/μL, CD45RA < 10%, or a restricted Vβ T-cell receptor repertoire (<13 of 24 families) were associated with the need for a second HCT or death. In the modern era, active infection continues to pose the greatest threat to survival for SCID patients. Although newborn screening has been effective in diagnosing SCID patients early in life, there is an urgent need to identify validated approaches through prospective trials to ensure that patients proceed to HCT infection free. The trial was registered at www.clinicaltrials.gov as #NCT01186913. 10.1182/blood-2017-05-781849
    Long-term immune reconstitution after matched unrelated hematopoietic stem cell transplantation for immunodeficiency. Kim Vy Hong-Diep,Reid Brenda,Atkinson Adelle,Upton Julia,Grunebaum Eyal,Roifman Chaim M The Journal of allergy and clinical immunology 10.1016/j.jaci.2017.10.015
    Combined haploidentical and umbilical cord blood transplantation for severe aplastic anemia: Unique hematopoietic reconstitution. Vatsayan Anant,Hashem Hasan,Nagle Kristen,Cabral Linda,Lazarus Hillard,Dalal Jignesh Hematology/oncology and stem cell therapy 10.1016/j.hemonc.2018.08.002
    Effect of Graft-versus-Host Disease Prophylaxis Regimens on T and B Cell Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation. Törlén Johan,Gaballa Ahmed,Remberger Mats,Mörk Lisa-Mari,Sundberg Berit,Mattsson Jonas,Uhlin Michael Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Lymphocyte reconstitution is pivotal for successful long-term outcome after allogeneic hematopoietic stem cell transplantation (HSCT), and conditioning regimen and post-transplantation immunosuppression are risk factors for prolonged immunodeficiency. Nevertheless, the effects of different immunosuppressive protocols on lymphocyte output and replicative capacity have not been investigated. Here we assessed T cell receptor excision circles (TREC), kappa-deleting recombination excision circles (KREC), and T cell telomere length (TL) as proxy markers for immune reconstitution in patients in a prospective randomized trial comparing graft-versus-host disease (GVHD) prophylaxis after transplantation (cyclosporine/methotrexate versus tacrolimus/sirolimus; n = 200). Results showed that medians of TREC, KREC, and TL were not significantly different between the prophylaxis groups at any assessment time point during follow-up (24 months), but the kinetics of TREC, KREC, and TL were significantly influenced by other transplantation-related factors. Older recipient age, the use of antithymocyte globulin before graft infusion, and use of peripheral blood stem cell grafts were associated with lower TREC levels, whereas acute GVHD transiently affected KREC levels. Patients with lymphocyte excision circle levels above the median at ≤6 months post-transplantation had reduced transplantation-related mortality and superior 5-year overall survival (P < .05). We noticed significant T cell telomere shortening in the patient population as a whole during follow-up. Our results suggest that lymphocyte reconstitution after transplantation is not altered by different immunosuppressive protocols. This study has been registered at ClinicalTrials.gov (identifier: NCT00993343). 10.1016/j.bbmt.2019.01.029
    Viral infections and immune reconstitution interaction after pediatric allogenic hematopoietic stem cell transplantation. Alexandersson Adam,Koskenvuo Minna,Tiderman Anette,Lääperi Mitja,Huttunen Pasi,Saarinen-Pihkala Ulla,Anttila Veli-Jukka,Lautenschlager Irmeli,Taskinen Mervi Infectious diseases (London, England) Viral infections are a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Although immune suppression plays a central role, the literature shows conflicting results on interplay between post-transplant immune reconstitution (IR) and viral infections. We prospectively studied viral infections and IR in 30 pediatric patients undergoing allogenic HSCT, with a follow-up time of 24 months. In total, 1337 blood (CMV, EBV, HHV-6, ADV and BKV) and urine (BKV and JCV) virus samples were analyzed. IR including B-cells (CD19+), T cells (CD3+, CD4+, CD8+) and NK-cells were measured. Clinical outcomes included overall survival (OS), non-relapse mortality (NRM), graft-versus-host disease (GVHD) and occurrence of blood culture positive bacterial infections. We found BKV reactivation to be most frequent, 47% of the children had viremia and 77% viruria. The frequencies of CMV, HHV-6 and adeno viremia were 37%, 37% and 6%, respectively. Viremias beyond 3 months post-HSCT were uncommon. Factors such as GVHD, use of steroids, EBV and CMV infections and pre-transplant irradiation affected IR. No specific viral infection or IR related factor was associated to OS or NRM. Viral infections and IR interact in a bi-directional manner. Accordingly, close follow-up of both IR and viral loads is warranted. 10.1080/23744235.2019.1650198
    Multivariate Analysis of Immune Reconstitution and Relapse Risk Scoring in Children Receiving Allogeneic Stem Cell Transplantation for Acute Leukemias. Transplantation direct A timely and effective immune reconstitution after hematopoietic stem cell transplantation (HSCT) is of crucial importance to enhance graft-versus-leukemia reaction in hematological malignancies. Several factors can influence the yield of this process, and new mathematical models are needed to describe this complex phenomenon. METHODS:We retrospectively analyzed immune reconstitution in the early post-HSCT period in a multicenter cohort of 206 pediatric patients affected by acute lymphoblastic leukemia, acute myeloblastic leukemia, and myelodysplastic syndrome who received their first allo-HSCT. All patients were in complete morphological remission at transplantation and were followed-up at least 26 mo post-HSCT. Blood samples for analysis of lymphocyte subset numbers were collected at day 100 (±20 d). RESULTS:The 2-y cumulative incidence of relapse was 22.2% (95% confidence interval [CI], 17.3-27). Using principal component analysis, we identified based on 16 input variables a new multivariate model that enables patients' description in a low-dimensional model, consisting of the first 2 principal components. We found that the numbers of CD3/CD4/CD8 lymphocyte subsets at day 100 post-HSCT and acute graft-versus-host disease had the greatest impact in preventing relapse. We ultimately derived a risk score defining high- or medium-low-risk groups with 2-y cumulative incidence of relapse: 35.3% (95% CI, 25.6-45) and 15.6% (95% CI, 10.1-20.7), respectively ( =0.001*). CONCLUSIONS:Our model describes immune reconstitution and its main influencing factors in the early posttransplantation period, presenting as a reliable model for relapse risk prediction. If validated, this model could definitely serve as a predictive tool and could be used for clinical trials or for individualized patient counseling. 10.1097/TXD.0000000000001226
    Reconstitution of NK cells expressing KIR3DL1 is associated with reduced NK cell activity and relapse of CML after allogeneic hematopoietic stem cell transplantation. International journal of hematology Although the prognosis of chronic myeloid leukemia (CML) in blastic crisis remains poor, some patients achieve long-term remission after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This may be attributable to graft-versus-leukemia (GVL) effects by donor lymphocytes, but their regulating mechanisms are unclear. Antitumor natural killer (NK) cell immunity is assumed to be important in CML, and we have previously shown that allelic polymorphisms of killer immunoglobulin-like receptors (KIRs) and histocompatibility leukocyte antigens (HLAs) are associated with the response of CML to tyrosine kinase inhibitors. Here, we report a case of CML in blastic phase who received HLA-matched but KIR3DL1 allelic-mismatched allo-HSCT. After transplant, decreased BCR-ABL transcript levels and enhanced NK cell activity were transiently observed. However, reconstitution of KIR3DL1-expressing NK cells occurred, which was associated with diminished NK cell activity and increased BCR-ABL. This case indicates the potential significance of KIR3DL1 in NK cell-mediated GVL activity following allo-HSCT. To the best of our knowledge, this is the first report to analyze the association between sequential KIR3DL1 expression and activity of NK cells after allo-HSCT. Selecting donors with KIR3DL1-null alleles may maintain competent GVL effects and provide improved outcomes in allo-HSCT for CML. 10.1007/s12185-019-02809-5
    Transplant of ex vivo incubated bone marrow with rIL -7 for the enhancement of immuno-hematopoietic reconstitution. Abdul-Hai Ali,Ben Yehuda Aryeh,Slavin Shimon,Or Reuven Leukemia & lymphoma Interleukin-7 (IL-7) is a critical cytokine in early B and T cell development. Peripheral T cell expansion and thymopoiesis and is a result of the ongoing reconstitution from uncommitted stem cells after transplant. We investigated the efficacy of ex vivo incubated bone marrow cells treated with recombinant human IL-7 (rIL-7) on subsequent in vivo murine models of syngeneic bone marrow (BM) transplant. After ex vivo culture with rIL-7, we observed a 1½-fold increase in BM cellularity; this increase was associated with an enhanced reconstitution of bone marrow cells and thymocytes at 45 days post-transplant. In addition to increased cellularity, lymphocytes from mice transplanted with cultured rIL-7 showed enhanced proliferative responses to mitogenic stimulation. These findings suggest rIL-7 to be a promising agent for the clinical application of treating immune deficiency and enhancing immuno-hematopoietic reconstitution of the stem cell auto/allograft. 10.3109/10428194.2015.1016935
    OCTET-CY: a phase II study to investigate the efficacy of post-transplant cyclophosphamide as sole graft-versus-host prophylaxis after allogeneic peripheral blood stem cell transplantation. Holtick Udo,Chemnitz Jens-Markus,Shimabukuro-Vornhagen Alexander,Theurich Sebastian,Chakupurakal Geothy,Krause Anke,Fiedler Anne,Luznik Leo,Hellmich Martin,Wolf Dominik,Hallek Michael,von Bergwelt-Baildon Michael,Scheid Christof European journal of haematology OBJECTIVE:Post-transplant cyclophosphamide is increasingly used as graft-versus-host disease (GvHD) prophylaxis in the setting of bone marrow transplantation. No data have been published on the use of single-agent GvHD prophylaxis with post-transplant cyclophosphamide in the setting of peripheral blood stem cell transplantation (PBSCT). METHODS:In a phase II trial, 11 patients with myeloma or lymphoma underwent conditioning with fludarabine and busulfan followed by T-replete PBSCT and application of 50 mg/kg/d of cyclophosphamide on day+3 and +4 without other concurrent immunosuppression (IS). RESULTS:Median time to leukocyte, neutrophil, and platelet engraftment was 18, 21, and 18 d. The incidence of grade II-IV and grade III-IV GvHD was 45% and 27%, with a non-relapse mortality (NRM) of 36% at one and 2 yr. After median follow-up of 927 d, overall and relapse-free survival was 64% and 34%. Three patients did not require any further systemic IS until day+100 and thereafter. Analysis of immune reconstitution demonstrated rapid T- and NK-cell recovery. B- and CD3+/CD161+NK/T-cell recovery was superior in patients not receiving additional IS. CONCLUSION:Post-transplant cyclophosphamide as sole IS in PBSCT is feasible and allows rapid immune recovery. Increased rates of severe acute GvHD explain the observed NRM and may advise a temporary combination partner such as mTor-inhibitors in the PBSCT setting. 10.1111/ejh.12541
    Immune Reconstitution Kinetics following Intentionally Induced Mixed Chimerism by Nonmyeloablative Transplantation. Kim Nayoun,Lee Hyunji,Shin Junghoon,Nam Young-Sun,Im Keon-Il,Lim Jung-Yeon,Lee Eun-Sol,Kang Young-Nam,Park Se-Ho,Cho Seok-Goo PloS one Establishing mixed chimerism is a promising approach for inducing donor-specific transplant tolerance. The establishment and maintenance of mixed chimerism may enable long-term engraftment of organ transplants while minimizing the use of immunosuppressants. Several protocols for inducing mixed chimerism have been reported; however, the exact mechanism underlying the development of immune tolerance remains to be elucidated. Therefore, understanding the kinetics of engraftment during early post-transplant period may provide insight into establishing long-term mixed chimerism and permanent transplant tolerance. In this study, we intentionally induced allogeneic mixed chimerism using a nonmyeloablative regimen by host natural killer (NK) cell depletion and T cell-depleted bone marrow (BM) grafts in a major histocompatibility complex (MHC)-mismatched murine model and analyzed the kinetics of donor (C57BL/6) and recipient (BALB/c) engraftment in the weeks following transplantation. Donor BM cells were well engrafted and stabilized without graft-versus-host disease (GVHD) as early as one week post-bone marrow transplantation (BMT). Donor-derived thymic T cells were reconstituted four weeks after BMT; however, the emergence of newly developed T cells was more obvious at the periphery as early as two weeks after BMT. Also, the emergence and changes in ratio of recipient- and donor-derived NKT cells and antigen presenting cells (APCs) including dendritic cells (DCs) and B cells were noted after BMT. Here, we report a longitudinal analysis of the development of donor- and recipient-originated hematopoietic cells in various lymphatic tissues of intentionally induced mixed chimerism mouse model during early post-transplant period. Through the understanding of immune reconstitution at early time points after nonmyeloablative BMT, we suggest guidelines on intentionally inducing durable mixed chimerism. 10.1371/journal.pone.0126318
    Reconstitution of Human Cytomegalovirus-Specific CD4+ T Cells is Critical for Control of Virus Reactivation in Hematopoietic Stem Cell Transplant Recipients but Does Not Prevent Organ Infection. Gabanti Elisa,Lilleri Daniele,Ripamonti Francesco,Bruno Francesca,Zelini Paola,Furione Milena,Colombo Anna A,Alessandrino Emilio P,Gerna Giuseppe Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation The relative contribution of human cytomegalovirus (HMCV)-specific CD4(+) and CD8(+) T cells to the control of HCMV infection in hematopoietic stem cell transplant (HSCT) recipients is still controversial. HCMV reactivation and HCMV-specific CD4(+) and CD8(+) T cell reconstitution were monitored for 1 year in 63 HCMV-seropositive patients receiving HSCT. HCMV reactivation was detected in all but 2 patients. In 20 of 63 (31.7%) patients (group 1) HCMV infection resolved spontaneously, whereas 32 of 63 (50.8%) patients (group 2) controlled the infection after a single short-course of pre-emptive therapy and the remaining 9 (14.3%) patients (group 3) suffered from relapsing episodes of HCMV infection, requiring multiple courses of antiviral therapy. The kinetics and magnitude of HCMV-specific CD8(+) T cell reconstitution were comparable among the 3 groups, but HCMV-specific CD4(+) T cells were lower in number in patients requiring antiviral treatment. HCMV-seronegative donors, as well as unrelated donors (receiving antithymocyte globulin) and acute graft-versus-host disease (GVHD) were associated with both delayed HCMV-specific CD4(+) T cell reconstitution and severity of infection. Conversely, these risk factors had no impact on HCMV-specific CD8(+) T cells. Eight patients with previous GVHD suffered from HCMV gastrointestinal disease, although in the presence of HCMV-specific CD4(+) and CD8(+) systemic immunity and undetectable HCMV DNA in blood. Reconstitution of systemic HCMV-specific CD4(+) T cell immunity is required for control of HCMV reactivation in adult HSCT recipients, but it may not be sufficient to prevent late-onset organ localization in patients with GVHD. HCMV-specific CD8(+) T cells contribute to control of HCMV infection, but only after HCMV-specific CD4(+) T cell reconstitution. 10.1016/j.bbmt.2015.08.002
    Possible Impact of Cytomegalovirus-Specific CD8 T Cells on Immune Reconstitution and Conversion to Complete Donor Chimerism after Allogeneic Stem Cell Transplantation. Ogonek Justyna,Varanasi Pavankumar,Luther Susanne,Schweier Patrick,Kühnau Wolfgang,Göhring Gudrun,Dammann Elke,Stadler Michael,Ganser Arnold,Borchers Sylvia,Koehl Ulrike,Weissinger Eva M,Hambach Lothar Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Complete donor chimerism is strongly associated with complete remission after allogeneic stem cell transplantation (allo-SCT) in patients with hematologic malignancies. Donor-derived allo-immune responses eliminate the residual host hematopoiesis and thereby mediate the conversion to complete donor chimerism. Recently, cytomegalovirus (CMV) reactivation was described to enhance overall T cell reconstitution, to increase graft-versus-host disease incidence, and to reduce the leukemia relapse risk. However, the link between CMV and allo-immune responses is still unclear. Here, we studied the relationship between CMV-specific immunity, overall T cell reconstitution, and residual host chimerism in 106 CMV-seropositive patients transplanted after reduced-intensity conditioning including antithymocyte globulin. In accordance with previous reports, the recovery of CMV-specific cytotoxic T cells (CMV-CTLs) was more frequent in CMV-seropositive recipients (R) transplanted from CMV-seropositive than from seronegative donors (D). However, once CMV-CTLs were detectable, the reconstitution of CMV-specific CTLs was comparable in CMV R+/D- and R+/D+ patients. CD3 and CD8 T cell reconstitution was significantly faster in patients with CMV-CTLs than in patients without CMV-CTLs both in the CMV R+/D- and R+/D+ setting. Moreover, CMV-CTL numbers correlated with CD3 and CD8 T cell numbers in both settings. Finally, presence of CMV-CTLs was associated with low host chimerism levels 3 months after allo-SCT. In conclusion, our data provide a first indication that CMV-CTLs in CMV-seropositive patients might trigger the reconstitution of T cells and allo-immune responses reflected by the conversion to complete donor chimerism. 10.1016/j.bbmt.2017.03.027
    Viral reactivations and associated outcomes in the context of immune reconstitution after pediatric hematopoietic cell transplantation. Admiraal Rick,de Koning Coco C H,Lindemans Caroline A,Bierings Marc B,Wensing Annemarie M J,Versluys A Birgitta,Wolfs Tom F W,Nierkens Stefan,Boelens Jaap Jan The Journal of allergy and clinical immunology BACKGROUND:Viral reactivations (VRs) after hematopoietic cell transplantation (HCT) contribute to significant morbidity and mortality. Timely immune reconstitution (IR) is suggested to prevent VR. OBJECTIVES:We studied the relation between IR (as a continuous predictor over time) and VR (as a time-varying predictor) and the relation between VR and other clinical outcomes. METHODS:In this retrospective analysis all patients receiving a first HCT between January 2004 and September 2014 were included. IR (CD3/CD4/CD8 T, natural killer, and B cells) was measured biweekly until 12 weeks and monthly thereafter. Main outcomes of interest were VR of adenovirus, EBV, human herpesvirus 6 (HHV6), cytomegalovirus (CMV), and BK virus screened weekly. Clinical outcomes included overall survival (OS), event-free-survival, nonrelapse mortality (NRM), and graft-versus-host disease. Cox proportional hazard and Fine and Gray competing risk models were used. RESULTS:Two hundred seventy-three patients (age, 0.1-22.7 years; median follow-up, 58 months) were included. Delayed CD4 reconstitution predicted reactivation of adenovirus (hazard ratio [HR], 0.995; P = .022), EBV (HR, 0.994; P = .029), and HHV6 (HR, 0.991; P = .012) but not CMV (P = .31) and BK virus (P = .27). Duration of adenovirus reactivation was shorter with timely CD4 reconstitution, which was defined as 50 × 10 cells/L or greater within 100 days. Adenovirus reactivation predicted lower OS (HR, 2.17; P = .0039) and higher NRM (HR, 2.96; P = .0008). Concomitant CD4 reconstitution abolished this negative effect of adenovirus reactivation (OS, P = .67; NRM, P = .64). EBV and HHV6 reactivations were predictors for the occurrence of graft-versus-host disease, whereas CMV and BK virus reactivation did not predict clinical outcomes. CONCLUSION:These results stress the importance of timely CD4 reconstitution. Strategies to improve CD4 reconstitution can improve HCT outcomes, including survival, and reduce the need for toxic antiviral therapies. 10.1016/j.jaci.2016.12.992
    Clinical impact of NK-cell reconstitution after reduced intensity conditioned unrelated cord blood transplantation in patients with acute myeloid leukemia: analysis of a prospective phase II multicenter trial on behalf of the Société Française de Greffe de Moelle Osseuse et Thérapie Cellulaire and Eurocord. Nguyen S,Achour A,Souchet L,Vigouroux S,Chevallier P,Furst S,Sirvent A,Bay J-O,Socié G,Ceballos P,Huynh A,Cornillon J,Francois S,Legrand F,Yakoub-Agha I,Michel G,Maillard N,Margueritte G,Maury S,Uzunov M,Bulabois C-E,Michallet M,Clement L,Dauriac C,Bilger K,Lejeune J,Béziat V,Rocha V,Rio B,Chevret S,Vieillard V Bone marrow transplantation Unrelated cord blood transplantation (UCBT) after a reduced intensity conditioning regimen (RIC) has extended the use of UCB in elderly patients and those with co-morbidities without an HLA-identical donor, although post-transplant relapse remains a concern in high-risk acute myeloid leukemia (AML) patients. HLA incompatibilities between donor and recipient might enhance the alloreactivity of natural killer (NK) cells after allogeneic hematopoietic stem-cell transplantation (HSCT). We studied the reconstitution of NK cells and KIR-L mismatch in 54 patients who underwent a RIC-UCBT for AML in CR in a prospective phase II clinical trial. After RIC-UCBT, NK cells displayed phenotypic features of both activation and immaturity. Restoration of their polyfunctional capacities depended on the timing of their acquisition of phenotypic markers of maturity. The incidence of treatment-related mortality (TRM) was correlated with low CD16 expression (P=0.043) and high HLA-DR expression (P=0.0008), whereas overall survival was associated with increased frequency of NK-cell degranulation (P=0.001). These features reflect a general impairment of the NK licensing process in HLA-mismatched HSCT and may aid the development of future strategies for selecting optimal UCB units and enhancing immune recovery. 10.1038/bmt.2017.122
    miR-625-3p is upregulated in CD8+ T cells during early immune reconstitution after allogeneic stem cell transplantation. Verma Kriti,Jyotsana Nidhi,Buenting Ivonne,Luther Susanne,Pfanne Angelika,Thum Thomas,Ganser Arnold,Heuser Michael,Weissinger Eva M,Hambach Lothar PloS one Alloreactive CD8+ T-cells mediate the curative graft-versus-leukaemia effect, the anti-viral immunity and graft-versus-host-disease (GvHD) after allogeneic stem cell transplantation (SCT). Thus, immune reconstitution with CD8+ T-cells is critical for the outcome of patients after allogeneic SCT. Certain miRNAs such as miR-146a or miR-155 play an important role in the regulation of post-transplant immunity in mice. While some miRNAs e.g. miR-423 or miR-155 are regulated in plasma or full blood during acute GvHD also in man, the relevance and expression profile of miRNAs in T-cells after allogeneic SCT is unknown. miR-625-3p has recently been described to be overexpressed in colorectal malignancies where it promotes migration, invasion and apoptosis resistance. Since similar regulative functions in cancer and T-cells have been described for an increasing number of miRNAs, we assumed a role for the cancer-related miR-625-3p also in T-cells. Here, we studied miR-625-3p expression selectively in CD8+ T-cells both in vitro and during immune reconstitution after allogeneic SCT in man. T-cell receptor stimulation lead to miR-625-3p upregulation in human CD8+ T-cells in vitro. Maintenance of elevated miR-625-3p expression levels was dependent on ongoing T-cell proliferation and was abrogated by withdrawal of interleukin 2 or the mTOR inhibitor rapamycin. Finally, miR-625-3p expression was analyzed in human CD8+ T-cells purified from 137 peripheral blood samples longitudinally collected from 74 patients after allogeneic SCT. miR-625-3p expression was upregulated on day 25 and on day 45, i.e. during the early phase of CD8+ T-cell reconstitution after allogeneic SCT and subsequently declined with completion of CD8+ T-cell reconstitution until day 150. In conclusion, this study has shown for the first time that miR-625-3p is regulated in CD8+ T-cells during proliferation in vitro and during early immune reconstitution after allogeneic SCT in vivo. These results warrant further studies to identify the targets and function of miR-625-3p in CD8+ T-cells and to analyze its predictive value for an effective immune reconstitution. 10.1371/journal.pone.0183828
    [Analysis of Hematopoietic Reconstitution in Auto-Peripheral Blood Hematopoietic Stem Cell Transplantation]. Chen Ying-Ying,Zhao Xiao-Li,Li Hong-Hua,Bo Jian,Zhao Yu,Jing Yu,Wang Quan-Shun,Gao Chun-Ji,Yu Li,Huang Wen-Rong Zhongguo shi yan xue ye xue za zhi OBJECTIVE:To explore the factors which may have influences on hematopoietic reconstitution of the auto-peripheral blood stem cell transplantation(auto-PBHSCT). METHODS:The successful rate, the time of hematopoietic reconstitution and implantation status at 28 days after transplantation of 177 patients received auto-PBSCT were retropectively analyzed, in order to explore the factors which may have influences on hematopoietic reconstitution. RESULTS:The median time of neutrophil recovery was 12 days (8-21 days), implantation rate was 98.9%, all patients' neutrophil were recovered in 28 days. The median time of platelet recovery was 17 days (7-420 days), implantation rate was 95.5%, the cumulative incidence of platelet recovery at day 28 was 80.8%. Univariate analysis showed that the CD34 cell number and the use of TPO had effect on neutrophils recovery time; the disease kinds, conditioning regimen and the infused CD34 cell number had influence on platelets recovery time. Multivariate analysis showed that the CD34 cell number was the independent influencing factor of neutrophils reconstitution time; the disease kinds, the CD34 cell number were the independent influencing factors of platelet reconstitution time. Disease kinds and the CD34 cell number were the independent influencing factors of hematopoietic reconstitution status of 28 days after transplantation. CONCLUSION:In auto-PBHSCT patients, disease kinds, conditioning regimen, the infused CD34 cell number and the use of TPO have been confirmed to be independent influencing factors on hematopoietic reconstitution. 10.7534/j.issn.1009-2137.2017.05.042
    Reconstitution of T and NK cells after haploidentical hematopoietic cell transplantation using αβ T cell-depleted grafts and the clinical implication of γδ T cells. Park Meerim,Im Ho Joon,Lee Yu-Jin,Park Nuree,Jang Seongsoo,Kwon Seog Woon,Park Chan-Jeoung,Choi Eun Seok,Koh Kyung Nam,Seo Jong Jin Clinical transplantation To investigate reconstitution of T and NK cells after αβ T lymphocyte-depleted haploidentical hematopoietic cell transplantation (HHCT) and the clinical implications of γδ T cells, we analyzed 50 pediatric patients who received 55 HHCTs using αβ T cell-depleted grafts. The number of CD3+ T cells and CD8+ T cells recovered rapidly and reached donor levels at days 180 and 60, respectively. Recovery of NK cells was rapid, and the median of NK cells at day 14 was comparable to the donor level. At day 14, median percentage of γδ T lymphocytes was 70.5%. After day 14, the percentage of γδ T cells gradually decreased, while the percentage of αβ T cells gradually increased. Patients with a low percentage (≤21%) of γδ T cells at day 30 had significantly higher incidence of cytomegalovirus (CMV) reactivation compared to patients with a high percentage (>70%) of γδ T cells (P < .01). In patients with acute leukemia, patients with high percentage of γδ T cells at day 30 showed significantly higher relapse-free survival compared to those with low percentage of γδ T cells (P = .02). Data suggest that early recovery of γδ T cells decreases the risk of CMV reactivation and leukemia relapse. 10.1111/ctr.13147
    Innate Immune Recovery Predicts CD4 T Cell Reconstitution after Hematopoietic Cell Transplantation. de Koning Coco,Langenhorst Jurgen,van Kesteren Charlotte,Lindemans Caroline A,Huitema Alwin D R,Nierkens Stefan,Boelens Jaap Jan Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Innate immune cells are the first to recover after allogeneic hematopoietic cell transplantation (HCT). Nevertheless, reports of innate immune cell recovery and their relation to adaptive recovery after HCT are largely lacking. Especially predicting CD4 T cell reconstitution is of clinical interest, because this parameter directly associates with survival chances after HCT. We evaluated whether innate recovery relates to CD4 T cell reconstitution probability and investigated differences between innate recovery after cord blood transplantation (CBT) and bone marrow transplantation (BMT). We developed a multivariate, combined nonlinear mixed-effects model for monocytes, neutrophils, and natural killer (NK) cell recovery after transplantation. A total of 205 patients undergoing a first HCT (76 BMT, 129 CBT) between 2007 and 2016 were included. The median age was 7.3years (range, .16 to 23). Innate recovery was highly associated with CD4 T cell reconstitution probability (P < .001) in multivariate analysis correcting for covariates. Monocyte (P < .001), neutrophil (P < .001), and NK cell (P < .001) recovery reached higher levels during the first 200days after CBT compared with BMT. The higher innate recovery after CBT may be explained by increased proliferation capacity (measured by Ki-67 expression) of innate cells in CB grafts compared with BM grafts (P = .041) and of innate cells in vivo after CBT compared with BMT (P = .048). At an individual level, patients with increased innate recovery after either CBT or BMT had received grafts with higher proliferating innate cells (CB; P = .004, BM; P = .01, respectively). Our findings implicate the use of early innate immune monitoring to predict the chance of CD4 T cell reconstitution after HCT, with respect to higher innate recovery after CBT compared with BMT. 10.1016/j.bbmt.2018.10.013
    Concise Review: Boosting T-Cell Reconstitution Following Allogeneic Transplantation-Current Concepts and Future Perspectives. Simons Laura,Cavazzana Marina,André Isabelle Stem cells translational medicine Allogeneic hematopoietic stem cell transplantation (HSCT) is the treatment of choice for a large number of malignant and nonmalignant (inherited) diseases of the hematopoietic system. Nevertheless, non-HLA identical transplantations are complicated by a severe T-cell immunodeficiency associated with a high rate of infection, relapse and graft-versus-host disease. Initial recovery of T-cell immunity following HSCT relies on peripheral expansion of memory T cells mostly driven by cytokines. The reconstitution of a diverse, self-tolerant, and naive T-cell repertoire, however, may take up to 2 years and crucially relies on the interaction of T-cell progenitors with the host thymic epithelium, which may be altered by GvHD, age or transplant-related toxicities. In this review, we summarize current concepts to stimulate reconstitution of a peripheral and polyclonal T-cell compartment following allogeneic transplantation such as graft manipulation (i.e., T-cell depletion), transfusion of ex vivo manipulated donor T cells or the exogenous administration of cytokines and growth factors to stimulate host-thymopoiesis with emphasis on approaches which have led to clinical trials. Particular attention will be given to the development of cellular therapies such as the ex vivo generation of T-cell precursors to fasten generation of a polyclonal and functional host-derived T-cell repertoire. Having been tested so far only in preclinical mouse models, clinical studies are now on the way to validate the efficacy of such T-cell progenitors in enhancing immune reconstitution following HSCT in various clinical settings. Stem Cells Translational Medicine 2019;00:1-8. 10.1002/sctm.18-0248
    The importance of the number of transplanted cells with dipeptidyl peptidase-4 expression on the haematopoietic recovery and lymphocyte reconstitution in patients with multiple myeloma after autologous haematopoietic stem-cell transplantation. Kopinska Anna,Krawczyk-Kulis Małgorzata,Dziaczkowska-Suszek Joanna,Bieszczad Katarzyna,Jagoda Krystyna,Kyrcz-Krzemien Slawomira Hematological oncology Autologous haematopoietic stem cell transplantation (AHSCT) remains recommended treatment in the first remission in multiple myeloma (MM). In earlier research it has been suggested that there is an influence of the expression of dipeptidyl peptidase-4 (CD26) on both the homing and lymphocyte reconstitution after AHSCT. The aim of the study is to investigate the influence of transplanted cells CD26+ on the haematopoietic recovery and lymphocyte reconstitution after AHSCT in MM. Forty eight patients with MM underwent AHSCT in our centre. Number of all CD26+ cells, CD26+ lymphocytes, CD26+ monocytes and CD26+ and CD34+ cells were measured in the harvested material. Number of lymphocyte's subpopulations (all lymphocytes CD3+, helpers, suppressors, natural killer (NK), cytotoxic NK and lymphocytes B) were measured in peripheral blood during regeneration after AHSCT. In both flow cytometry was used. On the basis of the analysis there was, as regards regeneration of haematopoietic cells after AHSCT, it was shown that a higher number of monocytes CD26+ improves the reconstitution of helper, suppressor and NK lymphocytes. A higher number of transplanted CD26+ lymphocytes accelerates the reconstitution of NK lymphocytes, whereas a higher number of all the cells CD26+ has a positive impact on the regeneration of cytotoxic NK lymphocytes. Copyright © 2015 John Wiley & Sons, Ltd. 10.1002/hon.2267
    Assessment of immune reconstitution status in recipients of a successful hematopoietic stem cell transplant from peripheral blood after reduced intensity conditioning. Jaime-Pérez José C,Villarreal-Villarreal César D,Méndez-Ramírez Nereida,Vázquez-Garza Eduardo,Salazar-Riojas Rosario,Gómez-Almaguer David Blood cells, molecules & diseases OBJECTIVE:To document immune reconstitution status after hematopoietic stem cell transplantation (HSCT) for malignant hematologic diseases. METHODS:Hematology patients who received a reduced intensity conditioning (RIC) were followed after successful allogeneic or autologous HSCT. Patients had at least 100days post-transplant. T, B and NK cells in peripheral blood (PB), and CD34+, CD133+ progenitor cells in bone marrow (BM) and peripheral blood (PB) were determined by flow cytometry. RESULTS:Twenty-seven HSCT recipients, 19 allogeneic and 8 autologous, were studied at a median 155 (100-721) days post-transplant. In the whole group the median value of CD34+ cells was 1.03% in the bone marrow and 0.04% in PB, whereas values for CD133+ cells were 0.39% and 0.13%, respectively, without statistical differences between autologous and allogeneic recipients. Significantly more B cells (CD3-/CD56-/CD19+) were found in the autologous compared to the allogeneic group, 12.6 vs. 5.01, p=0.04. An increased number of CD8+ lymphocytes with a 0.63 CD4:CD8 relationship was documented in PB. CONCLUSION:In clinically recovered autologous and allogeneic HSCT recipients BM and PB CD34+/CD133+ hematoprogenitor homeostasis is maintained within normal ranges, with better B-cell reconstitution in the autologous group. 10.1016/j.bcmd.2016.03.001
    Immune reconstitution post allogeneic transplant and the impact of immune recovery on the risk of infection. Mehta Rohtesh S,Rezvani Katayoun Virulence Infection is the leading cause of non-relapse mortality after allogeneic haematopoietic cell transplantation (HCT). This occurs as a result of dysfunction to the host immune system from the preparative regimen used prior to HCT, combined with a delay in reconstitution of the donor-derived immune system after HCT. In this article, we elaborate on the process of immune reconstitution post-HCT that begins with the innate system and is followed by recovery of adaptive immunity. Simultaneously, we describe how the tempo of immune reconstitution influences the risk of various infections. We explain some of the key differences in immune reconstitution and the consequent risk of infections in recipients of peripheral blood stem cell, bone marrow or umbilical cord blood grafts. Other factors that impact on immune recovery are also highlighted. Finally, we allude to various strategies that are being tested to enhance immune reconstitution post-HCT. 10.1080/21505594.2016.1208866
    Coinfection with Human Cytomegalovirus Genetic Variants in Transplant Recipients and Its Impact on Antiviral T Cell Immune Reconstitution. Smith Corey,Brennan Rebekah M,Tey Siok-Keen,Smyth Mark J,Burrows Scott R,Miles John J,Hill Geoffrey R,Khanna Rajiv Journal of virology UNLABELLED:Reconstitution of T cell immunity is absolutely critical for the effective control of virus-associated infectious complications in hematopoietic stem cell transplant (HSCT) recipients. Coinfection with genetic variants of human cytomegalovirus (CMV) in transplant recipients has been linked to clinical disease manifestation; however, how these genetic variants impact T cell immune reconstitution remains poorly understood. In this study, we have evaluated dynamic changes in the emergence of genetic variants of CMV in HSCT recipients and correlated these changes with reconstitution of antiviral T cell responses. In an analysis of single nucleotide polymorphisms within sequences encoding HLA class I-restricted CMV epitopes from the immediate early 1 gene of CMV, coinfection with genetically distinct variants of CMV was detected in 52% of patients. However, in spite of exposure to multiple viral variants, the T cell responses in these patients were preferentially directed to a limited repertoire of HLA class I-restricted CMV epitopes, either conserved, variant, or cross-reactive. More importantly, we also demonstrate that long-term control of CMV infection after HSCT is primarily mediated through the efficient induction of stable antiviral T cell immunity irrespective of the nature of the antigenic target. These observations provide important insights for the future design of antiviral T cell-based immunotherapeutic strategies for transplant recipients, emphasizing the critical impact of robust immune reconstitution on efficient control of viral infection. IMPORTANCE:Infection and disease caused by human cytomegalovirus (CMV) remain a significant burden in patients undergoing hematopoietic stem cell transplantation (HSCT). The establishment of efficient immunological control, primarily mediated by cytotoxic T cells, plays a critical role in preventing CMV-associated disease in transplant recipients. Recent studies have also begun to investigate the impact genetic variation in CMV has upon disease outcome in transplant recipients. In this study, we sought to investigate the role T cell immunity plays in recognizing and controlling genetic variants of CMV. We demonstrate that while a significant proportion of HSCT recipients may be exposed to multiple genetic variants of CMV, this does not necessarily lead to immune control mediated via recognition of this genetic variation. Rather, immune control is associated with the efficient establishment of a stable immune response predominantly directed against immunodominant conserved T cell epitopes. 10.1128/JVI.00297-16
    Predicting CD4 T-Cell Reconstitution Following Pediatric Hematopoietic Stem Cell Transplantation. Hoare R L,Veys P,Klein N,Callard R,Standing J F Clinical pharmacology and therapeutics Hematopoietic stem cell transplantation (HSCT) is an increasingly common treatment for children with a range of hematological disorders. Conditioning with cytotoxic chemotherapy and total body irradiation leaves patients severely immunocompromised. T-cell reconstitution can take several years due to delayed restoration of thymic output. Understanding T-cell reconstitution in children is complicated by normal immune system maturation, heterogeneous diagnoses, and sparse uneven sampling due to the long time spans involved. We describe here a mechanistic mathematical model for CD4 T-cell immune reconstitution following pediatric transplantation. Including relevant biology and using mixed-effects modeling allowed the factors affecting reconstitution to be identified. Bayesian predictions for the long-term reconstitution trajectories of individual children were then obtained using early post-transplant data. The model was developed using data from 288 children; its predictive ability validated on data from a further 75 children, with long-term reconstitution predicted accurately in 81% of the patients. 10.1002/cpt.621
    Human herpesvirus 6 viremia affects T-cell reconstitution after allogeneic hematopoietic stem cell transplantation. de Koning Coco,Admiraal Rick,Nierkens Stefan,Boelens Jaap Jan Blood advances Human herpesvirus 6 (HHV6) viremia is a common cause of morbidity following allogeneic hematopoietic cell transplantation (HCT). We previously associated T-cell reconstitution with HHV6 viremia. Here, we investigated whether HHV6 viremia affects T-cell reconstitution after HCT in a time-dependent retrospective analysis. We included 273 pediatric patients (0.1-22.7 years; median follow-up, 58 months) receiving a first HCT between 2004 and 2014. HHV6 was screened weekly in plasma via polymerase chain reaction and occurred in 79 patients (29%) at a median time of 19 days after transplant. Main outcome of interest was immune reconstitution (IR) (CD3/CD4/CD8 T cells), measured biweekly until 12 weeks and monthly thereafter. Cox proportional-hazard models were used with IR and HHV6 as time-dependent variables in multivariate analysis with serotherapy in conditioning, graft source, graft-versus-host disease, age, and other viruses (Epstein-Barr virus, cytomegalovirus, and adenovirus) as covariates. Only patients with very high HHV6 viremia (>10 copies/mL) showed hampered CD4 (hazard ratio [HR], 0.913; 95% confidence interval [CI], 0.892-0.934; < .001) and CD8 (HR, 0.912; 95% CI, 0.891-0.933; < .001) reconstitution in comparison with patients without HHV6, from ∼6 months after HCT. Especially naïve CD4 IR was affected ( = .028) but not effector memory CD4 IR ( = .33). Interestingly, T-cell reconstitution was improved in patients treated with antivirals (HR, 1.572; 95% CI, 1.463-1.690; < .001). These findings suggest that HHV6 viremia affects late but not early T-cell reconstitution. 10.1182/bloodadvances.2017012724
    Early Reconstitution of NK and γδ T Cells and Its Implication for the Design of Post-Transplant Immunotherapy. de Witte Moniek A,Sarhan Dhifaf,Davis Zachary,Felices Martin,Vallera Daniel A,Hinderlie Peter,Curtsinger Julie,Cooley Sarah,Wagner John,Kuball Jurgen,Miller Jeffrey S Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Relapse is the most frequent cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Natural killer (NK) cells and γδ T cells reconstitute early after allo-HSCT, contribute to tumor immunosurveillance via major histocompatibility complex-independent mechanisms and do not induce graft-versus-host disease. Here we performed a quantitative and qualitative analysis of the NK and γδ T cell repertoire in healthy individuals, recipients of HLA-matched sibling or unrelated donor allo-HSCT (MSD/MUD-HSCT) and umbilical cord blood-HSCT (UCB-HSCT). NK cells are present at high frequencies in all allo-HSCT recipients. Immune reconstitution (IR) of vδ2 cells depended on stem cell source. In MSD/MUD-HSCT recipients, vδ2 comprise up to 8% of the total lymphocyte pool, whereas vδ2 T cells are barely detectable in UCB-HSCT recipients. Vδ1 IR was driven by CMV reactivation and was comparable between MSD/MUD-HSCT and UCB-HSCT. Strategies to augment NK cell mediated tumor responses, similar to IL-15 and antibodies, also induced vδ2 T cell responses against a variety of different tumor targets. Vδ1 γδ T cells were induced less by these same stimuli. We also identified elevated expression of the checkpoint inhibitory molecule TIGIT (T cell Ig and ITIM domain), which is also observed on tumor-infiltrating lymphocytes and epidermal γδ T cells. Collectively, these data show multiple strategies that can result in a synergized NK and γδ T cell antitumor response. In the light of recent developments of low-toxicity allo-HSCT platforms, these interventions may contribute to the prevention of early relapse. 10.1016/j.bbmt.2018.02.023
    Quantiferon-Cytomegalovirus assay: A potentially useful tool in the evaluation of CMV-specific CD8+ T-cell reconstitution in pediatric hematopoietic stem cell transplant patients. Paouri Bilio,Soldatou Alexandra,Petrakou Eftihia,Theodosaki Maria,Tsentidis Charalampos,Kaisari Katerina,Oikonomopoulou Christina,Matsas Minos,Goussetis Eugenios Pediatric transplantation Pediatric HSCT recipients are at high risk for CMV reactivation due to their immature immune system and therapy following transplantation. Reconstitution of CMV-specific T-cell immunity is associated with control and protection against CMV. The clinical utility of monitoring CMV-specific CMI to predict CMV viremia in pediatric HSCT patients using the Quantiferon-CMV (QIAGEN ) test was investigated prospectively. Thirty-seven pediatric allogeneic HSCT recipients were enrolled from 3/2010-6/2012. CMV viremia was detected via weekly real-time PCR. The Quantiferon-CMV test was conducted pretransplant, early after transplantation, 30, 90, 180, 270, and 360 days post-transplantation. The incidence of CMV viremia was 51% (19/37) with half of the episodes within ≤30 days post-transplant. Fifteen patients showed CMV-specific immunity (average of 82 days). The cumulative incidence of CMV reactivation in patients who developed CMV-specific immunity was lower than those who did not (15% vs 53%; P = .023). The ROC statistical analysis showed that the AUC was 0.725 in predicting viremia, for Quantiferon-CMV test. In this cohort, the Quantiferon-CMV assay was a valuable method for identifying pediatric HSCT patients at high risk for CMV viremia, suggesting potential clinical utility to individualize patient's management post-transplant. 10.1111/petr.13220
    Successful long-term hematological and immunological reconstitution by autologous cord blood transplantation combined with post-transplant immunosuppression in two children with severe aplastic anemia. Avgerinou Georgia,Oikonomopoulou Christina,Kaisari Aikaterini,Ioannidou Elda,Komitopoulou Anna,Paisou Anna,Tourkantoni Natalia,Filippidou Maria,Kattamis Antonios,Vessalas George,Peristeri Ioulia,Goussetis Evgenios,Kitra Vasiliki Pediatric transplantation aUCBT is a valuable curative option in pediatric patients with refractory idiopathic SAA and no available matched sibling or unrelated donors. Experience in the use of autologous cord blood units in patients with SAA is limited and private for-profit cord blood-banking programs are controversial. We report the successful treatment of two patients with SAA, aged 15 and 24 months, with autologous cord blood combined with immunosuppression. After conditioning with 200 mg/kg cyclophosphamide and ATG, 7.5 mg/kg, 32.2 × 10 /kg, and 3.8 × 10 /kg autologous cord blood nucleated cells were infused, respectively. One of our patients underwent transplantation after failure of IST. Both patients received post-transplant immunosuppression with cyclosporine for 12 months. They remain disease-free 6 years post-transplantation. 10.1111/petr.13320
    Immune reconstitution following hematopoietic stem cell transplantation using different stem cell sources. Elfeky Reem,Lazareva Arina,Qasim Waseem,Veys Paul Expert review of clinical immunology : Adequate immune reconstitution post-HSCT is crucial for the success of transplantation, and can be affected by both patient- and transplant-related factors. : A systematic literature search in PubMed, Scopus, and abstracts of international congresses is performed to investigate immune recovery posttransplant. In this review, we discuss the pattern of immune recovery in the post-transplant period focusing on the impact of stem cell source (bone marrow, peripheral blood stem cells, and cord blood) on immune recovery and HSCT outcome. We examine the impact of serotherapy on immune reconstitution and the need to tailor dosing of serotherapy agents when using different stem cell sources. We discuss new techniques being used particularly with cord blood and haploidentical grafts to improve immune recovery in each scenario. : Cord blood T cells provide a unique CD4+ biased immune reconstitution. Initial studies using targeted serotherapy with cord grafts showed improved immune recovery with limited alloreactivity. Two competing haploidentical approaches have developed in recent years including TCRαβ/CD19 depleted grafts and post-cyclophosphamide haplo-HSCT. Both approaches have comparable survival rates with limited alloreactivity. However, delayed immune reconstitution is still an ongoing problem and could be improved by modified donor lymphocyte infusions from the same haploidentical donor. 10.1080/1744666X.2019.1612746
    Kinetics of immune cell reconstitution predict survival in allogeneic bone marrow and G-CSF-mobilized stem cell transplantation. Waller Edmund K,Logan Brent R,Fei Mingwei,Lee Stephanie J,Confer Dennis,Howard Alan,Chandrakasan Shanmuganathan,Anasetti Claudio,Fernando Shanelle M,Giver Cynthia R Blood advances The clinical utility of monitoring immune reconstitution after allotransplant was evaluated using data from Blood and Marrow Transplant Clinical Trials Network BMT CTN 0201 (NCT00075816), a multicenter randomized study of unrelated donor bone marrow (BM) vs granulocyte colony-stimulating factor (G-CSF)-mobilized blood stem cell (G-PB) grafts. Among 410 patients with posttransplant flow cytometry measurements of immune cell subsets, recipients of G-PB grafts had faster T-cell reconstitution than BM recipients, including more naive CD4 T cells and T-cell receptor excision circle-positive CD4 and CD8 T cells at 3 months, consistent with better thymic function. Faster reconstitution of CD4 T cells and naive CD4 T cells at 1 month and CD8 T cells at 3 months predicted more chronic graft-versus-host disease (GVHD) but better survival in G-PB recipients, but consistent associations of T-cell amounts with GVHD or survival were not seen in BM recipients. In contrast, a higher number of classical dendritic cells (cDCs) in blood samples at 3 months predicted better survival in BM recipients. Functional T-cell immunity measured in vitro by cytokine secretion in response to stimulation with cytomegalovirus peptides was similar when comparing blood samples from BM and G-PB recipients, but the degree to which acute GVHD suppressed immune reconstitution varied according to graft source. BM, but not G-PB, recipients with a history of grades 2-4 acute GVHD had lower numbers of B cells, plasmacytoid dendritic cells, and cDCs at 3 months. Thus, early measurements of T-cell reconstitution are predictive cellular biomarkers for long-term survival and response to GVHD therapy in G-PB recipients, whereas more robust DC reconstitution predicted better survival in BM recipients. 10.1182/bloodadvances.2018029892
    Early Natural Killer Cell Reconstitution Predicts Overall Survival in T Cell-Replete Allogeneic Hematopoietic Stem Cell Transplantation. Minculescu Lia,Marquart Hanne Vibeke,Friis Lone Smidstrup,Petersen Soeren Lykke,Schiødt Ida,Ryder Lars Peter,Andersen Niels Smedegaard,Sengeloev Henrik Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Early immune reconstitution plays a critical role in clinical outcome after allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells are the first lymphocytes to recover after transplantation and are considered powerful effector cells in HSCT. We aimed to evaluate the clinical impact of early NK cell recovery in T cell-replete transplant recipients. Immune reconstitution was studied in 298 adult patients undergoing HSCT for acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome from 2005 to 2013. In multivariate analysis NK cell numbers on day 30 (NK30) > 150 cells/µL were independently associated with superior overall survival (hazard ratio, .79; 95% confidence interval, .66 to .95; P = .01). Cumulative incidence analyses showed that patients with NK30 > 150 cells/µL had significantly less transplant-related mortality (TRM), P = .01. Patients with NK30 > 150 cells/µL experienced significantly lower numbers of life-threatening bacterial infections as well as viral infections, including cytomegalovirus. No association was observed in relation to relapse. These results suggest an independent protective effect of high early NK cell reconstitution on TRM that translates into improved overall survival after T cell-replete HSCT. 10.1016/j.bbmt.2016.09.006
    Angiogenic Factors Correlate with T Cell Immune Reconstitution and Clinical Outcomes after Double-Unit Umbilical Cord Blood Transplantation in Adults. Politikos Ioannis,T Kim Haesook,Karantanos Theodoros,Brown Julia,McDonough Sean,Li Lequn,Cutler Corey,Antin Joseph H,Ballen Karen K,Ritz Jerome,Boussiotis Vassiliki A Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Umbilical cord blood (UCB) is a valuable graft source for allogeneic hematopoietic stem cell transplantation (HSCT) in patients who lack adult donors. UCB transplantation (UCBT) in adults results in delayed immune reconstitution, leading to high infection-related morbidity and mortality. Angiogenic factors and markers of endothelial dysfunction have biologic and prognostic significance in conventional HSCT, but their role in UCBT has not been investigated. Furthermore, the interplay between angiogenesis and immune reconstitution has not been studied. Here we examined whether angiogenic cytokines, angiopoietin-1 (ANG-1) and vascular endothelial growth factor (VEGF), or markers of endothelial injury, thrombomodulin (TM) and angiopoietin-2 (ANG-2), associate with thymic regeneration as determined by T cell receptor excision circle (TREC) values and recovery of T cell subsets, as well as clinical outcomes in adult recipients of UCBT. We found that plasma levels of ANG-1 significantly correlated with the reconstitution of naive CD4CD45RA and CD8CD45RA T cell subsets, whereas plasma levels of VEGF displayed a positive correlation with CD4CD45RO T cells and regulatory T cells and a weak correlation with TRECs. Assessment of TM and ANG-2 revealed a strong inverse correlation of both factors with naive T cells and TRECs. The angiogenic capacity of each patient's plasma, as determined by an in vitro angiogenesis assay, positively correlated with VEGF levels and with reconstitution of CD4 T cell subsets. Higher VEGF levels were associated with worse progression-free survival and higher risk of relapse, whereas higher levels of TM were associated with chronic graft-versus-host disease and nonrelapse mortality. Thus, angiogenic factors may serve as valuable markers associated with T cell reconstitution and clinical outcomes after UCBT. 10.1016/j.bbmt.2016.10.013
    Graft-Derived Reconstitution of Mucosal-Associated Invariant T Cells after Allogeneic Hematopoietic Cell Transplantation. Bhattacharyya Abir,Hanafi Laïla-Aïcha,Sheih Alyssa,Golob Jonathan L,Srinivasan Sujatha,Boeckh Michael J,Pergam Steven A,Mahmood Sajid,Baker Kelsey K,Gooley Ted A,Milano Filippo,Fredricks David N,Riddell Stanley R,Turtle Cameron J Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Mucosal-associated invariant T (MAIT) cells express a semi-invariant Vα7.2 T cell receptor (TCR) that recognizes ligands from distinct bacterial and fungal species. In neonates, MAIT cells proliferate coincident with gastrointestinal (GI) bacterial colonization. In contrast, under noninflammatory conditions adult MAIT cells remain quiescent because of acquired regulation of TCR signaling. Effects of inflammation and the altered GI microbiota after allogeneic hematopoietic cell transplantation (HCT) on MAIT cell reconstitution have not been described. We conducted an observational study of MAIT cell reconstitution in myeloablative (n = 41) and nonmyeloablative (n = 66) allogeneic HCT recipients and found that despite a rapid and early increase to a plateau at day 30 after HCT, MAIT cell numbers failed to normalize for at least 1 year. Cord blood transplant recipients and those who received post-HCT cyclophosphamide for graft versus host disease (GVHD) prophylaxis had profoundly impaired MAIT cell reconstitution. Sharing of TCRβ gene sequences between MAIT cells isolated from HCT grafts and blood of recipients after HCT showed early MAIT cell reconstitution was due at least in part to proliferation of MAIT cells transferred in the HCT graft. Inflammatory cytokines were required for TCR-dependent MAIT cell proliferation, suggesting that bacterial Vα7.2 TCR ligands might promote MAIT cell reconstitution after HCT. Robust MAIT cell reconstitution was associated with an increased GI abundance of Blautia spp. MAIT cells suppressed proliferation of conventional T cells consistent with a possible regulatory role. Our data identify modifiable factors impacting MAIT cell reconstitution that could influence the risk of GVHD after HCT. 10.1016/j.bbmt.2017.10.003
    The potential association of CMV-specific CD8+ T lymphocyte reconstitution with the risk of CMV reactivation and persistency in post allogeneic stem cell transplant patients. Shams El-Din Ahmed Ali,El-Desoukey Nermeen Ahmed,Amin Tawadrous Dalia Gamil,Fouad Neveen Mohammed Baha El-Din,Abdel-Mooti Mohammed,Hotar Said Fathy Hematology (Amsterdam, Netherlands) OBJECTIVES:development of cytomegalovirus (CMV)-specific CD8+ T cell response is crucial in preventing symptomatic CMV infection specially, in stem cell transplant (SCT) patients. The aim of this study was to evaluate CMV-specific CD8+ T cell reconstitution in allogeneic SCT recipients and to study the possible association between CMV-specific CD8+ T cell recovery with protection from CMV reactivation and persistency. METHODS:Human leuKocyte antigen (HLA)-tetramers were used for CMV-specific CD8+ cell quantitation by Flow cytometry in twenty post-allogeneic SCT patients. RESULTS:Nine patients (45%) developed rapid recovery of CMV-specific CD8+ cells, among them; 7 patients (78%) had no CMV reactivation in the first 95 days post-transplant. Five patients had developed persistent CMV viremia; all of them had not developed CMV-specific CD8+ recovery till day 95 post-transplant. Patients with persistent CMV viremia had a statistically significant lower means of CMV-specific CD8+ percent and absolute count compared to those without persistent viremia (p = .001, .015), respectively. DISCUSSION:The incidence of CMV reactivation and persistency was higher among patients with delayed CMV-specific CD8+ reconstitution in the first 95 days post-transplant. CONCLUSION:CMV-specific CD8+ cells can help in categorizing patients into risk groups: (early recovery/low risk) and (delayed recovery/increased risk), this tool may guide clinicians in the selection of patients who may profit from prophylactic antiviral therapy and frequent viral monitoring. 10.1080/10245332.2017.1422686
    Impact on early outcomes and immune reconstitution of high-dose post-transplant cyclophosphamide vs anti-thymocyte globulin after reduced intensity conditioning peripheral blood stem cell allogeneic transplantation. Retière Christelle,Willem Catherine,Guillaume Thierry,Vié Henri,Gautreau-Rolland Laetitia,Scotet Emmanuel,Saulquin Xavier,Gagne Katia,Béné Marie C,Imbert Berthe-Marie,Clemenceau Beatrice,Peterlin Pierre,Garnier Alice,Chevallier Patrice Oncotarget We have compared prospectively the outcome and immune reconstitution of patients receiving either post-transplant cyclophosphamide (PTCY) ( = 30) or anti-thymocyte globulin ATG ( = 15) as Graft-versus-host disease (GVHD) prophylaxis after reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell (PBSC) transplantation (allo-SCT). The outcome and immune reconstitution of patients receiving either of these two regimens were compared prospectively. This study allowed also to investigate the impact of PTCY between haplo-identical vs matched donors and of clofarabine as part of the RIC regimen. The γ/δ T-cells, α/β T-cells (CD8 and CD4), NK T-cells, NK cells, B-cells, Tregs and monocytes were analyzed by flow cytometry from a total of 583 samples. In the PTCY group significant delayed platelets recovery, higher CD3+ donor chimerism, higher HHV-6 and lower EBV reactivations were observed. Early survival advantage for CD4+ T-cells, Tregs and α/β T-cells was documented in the PTCY group while it was the case for α/β T-cells, NK cells and monocytes in the ATG group. Higher counts of NK and monocytes were observed at days +30 and/or day+60 in the ATG group. Both results were retained even in the case of mismatched donors. However, higher percentages of CD4+ T-cells, α/β T-cells and Tregs were observed with haplo-identical donors in the PTCY group. Finally, clofarabine was responsible for early survival advantage of NK T-cells in the PTCY group while it abrogated the early survival advantage of γ/δ T-cells in the ATG group. In conclusion, there are marked differences in the immunological effects of ATG vs PTCY as GVHD prophylaxis for RIC PBSC allo-SCT. 10.18632/oncotarget.24328
    Rapid reconstitution of CMV-specific T-cells after stem-cell transplantation. Widmann Thomas,Sester Urban,Schmidt Tina,Gärtner Barbara C,Schubert Jörg,Pfreundschuh Michael,Sester Martina European journal of haematology OBJECTIVE:As reconstitution of virus-specific T-cells is critical to control cytomegalovirus (CMV)-viremia following stem-cell transplantation (SCT), we characterized the dynamics in CMV-specific T-cell reconstitution after SCT. METHODS:Cytomegalovirus-specific T-cells from 51 SCT-recipients were prospectively quantified and phenotypically characterised by intracellular cytokine-staining after specific stimulation and HLA class-I-specific pentamers using flow cytometry. RESULTS:Cytomegalovirus-specific CD4 T-cells reconstituted after a median of 2.3 (IQR, 2.0-3.0) weeks following autografting, and 4.0 (IQR, 3.0-5.6) weeks after allografting, with CMV-specific T-cells originating from donors and/or recipients. The time for reconstitution of CMV-specific CD4 and CD8 T-cells did not differ (P = .58). Factors delaying the time to initial reconstitution of CMV-specific CD4 T-cells included a negative recipient serostatus (P = .016) and CMV-viremia (P = .026). Percentages of CMV-specific CD4 T-cells significantly increased over time and reached a plateau after 90 days (P = .043). Relative CMV-specific CD4 T-cell levels remained higher in long-term transplant recipients compared with those in controls (P < .0001). However, due to persisting lymphopenia, absolute numbers of CMV-specific T-cells were similar as in controls. CONCLUSION:Cytomegalovirus-specific T-cells rapidly reconstitute after SCT and their percentages remain high in the long term. In the face of persistent lymphopenia, this results in similar absolute numbers of CMV-specific T-cells as in controls to ensure sufficient pathogen control. 10.1111/ejh.13077
    HHV-6B infection, T-cell reconstitution, and graft-vs-host disease after hematopoietic stem cell transplantation. Phan Tuan L,Pritchett Joshua C,Leifer Cynthia,Zerr Danielle M,Koelle David M,Di Luca Dario,Lusso Paolo Bone marrow transplantation Successful and sustained CD4 T-cell reconstitution is associated with increased survival after hematopoietic cell transplantation (HCT), but opportunistic infections may adversely affect the time and extent of immune reconstitution. Human herpesvirus 6B (HHV-6B) efficiently infects CD4 T cells and utilizes as a receptor CD134 (OX40), a member of the TNF superfamily that antagonizes regulatory T-cell (T) activity. Reactivation of HHV-6B has been associated with aberrant immune reconstitution and acute graft-versus-host disease (aGVHD) after HCT. Given that T counts are negatively correlated with aGVHD severity, we postulate that one mechanism for the poor CD4 T-cell reconstitution observed shortly after transplant may be HHV-6B infection and depletion of peripheral (extra-thymic) CD4 T cells, including a subpopulation of T cells. In turn, this may trigger a series of adverse events resulting in poor clinical outcomes such as severe aGVHD. In addition, recent evidence has linked HHV-6B reactivation with aberrant CD4 T-cell reconstitution late after transplantation, which may be mediated by a different mechanism, possibly related to central (thymic) suppression of T-cell reconstitution. These observations suggest that aggressive management of HHV-6B reactivation in transplant patients may facilitate CD4 T-cell reconstitution and improve the quality of life and survival of HCT patients. 10.1038/s41409-018-0225-2
    B Cell Reconstitution and Influencing Factors After Hematopoietic Stem Cell Transplantation in Children. van der Maas Nicolaas G,Berghuis Dagmar,van der Burg Mirjam,Lankester Arjan C Frontiers in immunology B cell reconstitution after hematopoietic stem cell transplantation (HSCT) is variable and influenced by different patient, donor, and treatment related factors. In this review we describe B cell reconstitution after pediatric allogeneic HST, including the kinetics of reconstitution of the different B cell subsets and the development of the B cell repertoire, and discuss the influencing factors. Observational studies show important roles for stem cell source, conditioning regimen, and graft vs. host disease in B cell reconstitution. In addition, B cell recovery can play an important role in post-transplant infections and vaccine responses to encapsulated bacteria, such as pneumococcus. A substantial number of patients experience impaired B cell function and/or dependency on Ig substitution after allogeneic HSCT. The underlying mechanisms are largely unresolved. The integrated aspects of B cell recovery after HSCT, especially BCR repertoire reconstitution, are awaiting further investigation using modern techniques in order to gain more insight into B cell reconstitution and to develop strategies to improve humoral immunity after allogeneic HSCT. 10.3389/fimmu.2019.00782
    Effect of Sirolimus on Immune Reconstitution Following Myeloablative Allogeneic Stem Cell Transplantation: An Ancillary Analysis of a Randomized Controlled Trial Comparing Tacrolimus/Sirolimus and Tacrolimus/Methotrexate (Blood and Marrow Transplant Clinical Trials Network/BMT CTN 0402). Gooptu Mahasweta,Kim Haesook T,Howard Alan,Choi Sung W,Soiffer Robert J,Antin Joseph H,Ritz Jerome,Cutler Corey S Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Although allogeneic hematopoietic cell transplantation (HCT) is a potentially curative therapy for hematologic neoplasms, one of its limiting toxicities continues to be graft-versus-host disease, both acute (aGVHD) and chronic (cGVHD). Sirolimus is a mammalian target of rapamycin inhibitor that has proven effective in GVHD prophylaxis in combination with a calcineurin inhibitor, such as tacrolimus. The impact of sirolimus on immune reconstitution has not been comprehensively investigated in vivo thus far, however. Here we present an ancillary analysis of the randomized study BMT-CTN 0402 that examined the effect of sirolimus on immune subsets post-transplantation. We further examine the association between different lymphocyte subsets and outcomes post-transplantation in each arm. BMT-CTN 0402 was a randomized trial (n = 304) comparing 2 GVHD prophylaxis regimens, tacrolimus/sirolimus (Tac/Sir) and tacrolimus/methotrexate (Tac/MTX), in patients with acute myelogenous leukemia, acute lymphoblastic leukemia, or myelodysplastic syndrome undergoing myeloablative HLA-matched HCT. There were no differences in 114-day GVHD-free survival (primary endpoint), aGVHD, cGVHD, relapse, or overall survival (OS) between the 2 arms. Of the 304 patients, 264 had available samples for the current immune reconstitution analysis. Blood samples were collected at 1, 3, 6, 12, and 24 months post-HCT. Multiparameter flow cytometry was performed at the project laboratory (Esoterix Clinical Trials Services) in a blinded fashion, and results for the 2 arms were compared. Multivariable Cox regression models, treating each phenotypic parameter as a time-dependent variable, were constructed to study the impact of reconstitution on clinical outcomes. There were no significant differences in patient and transplantation characteristics between the Tac/Sir and Tac/MTX arms in this analysis. Absolute lymphocyte count and CD3 cell, CD4 cell, and conventional T cell (Tcon) counts were significantly decreased in the Tac/Sir arm for up to 3 months post-HCT, whereas CD8 cells recovered even more slowly (up to 6 months) in this arm. Interestingly, there was no clear difference in the absolute number of regulatory T cells (Tregs, defined as CD4CD25 cells) between the 2 arms at any point post-HCT; however, the Treg:Tcon ratio was significantly greater in the Tac/Sir arm in the first 3 months after HCT. B lymphocyte recovery was significantly compromised in the Tac/Sir arm from 1 month to 6 months after HCT, whereas natural killer cell reconstitution was not affected in the Tac/Sir arm. In the outcomes analysis, higher numbers of CD3 cells, CD4 cells, CD8 cells, and Tregs were associated with better OS. Neither Treg numbers nor the Treg:Tcon ratio was correlated with GVHD. Our findings indicate that Tac/Sir has a more profound T cell suppressive effect than the combination of Tac/MTX in the early post-transplantation period, and particularly compromises the recovery of CD8 T cells, which have been implicated in aGVHD. Sirolimus used in vivo with tacrolimus does not appear to result in increased absolute numbers of Tregs, but might have a beneficial effect on the Treg:Tcon balance in the first 3 months after transplantation. Nonetheless, no differences in aGVHD or cGVHD between the 2 arms were observed in the parent randomized trial. Calcineurin-inhibitor free, sirolimus-containing GVHD prophylaxis strategies, incorporating other novel agents, should be investigated further to maximize the potential favorable effect of sirolimus on Treg:Tcon balance in the post-transplantation immune repertoire. Sirolimus significantly compromises B cell recovery in the first 6 months post-HCT, with potential complex effects on cGVHD that merit further study. 10.1016/j.bbmt.2019.06.029
    Impact of Cytomegalovirus Reactivation and Natural Killer Reconstitution on Outcomes after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Analysis. Ando Taiki,Suzuki Taisei,Ishiyama Yasufumi,Koyama Satoshi,Tachibana Takayoshi,Tanaka Masatsugu,Kanamori Heiwa,Nakajima Hideaki Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Cytomegalovirus (CMV) reactivation and natural killer (NK) cell reconstitution are well-recognized immunologic events occurring after allogeneic stem cell transplantation (allo-SCT). We aimed to study the outcome of CMV reactivation (CMVR) and NK cell reconstitution in patients with hematologic malignancies after allo-SCT. We retrospectively studied 246 adult patients (152 men, 94 women; median age, 51 years [range, 18 to 69]) who underwent allo-SCT for hematologic malignancies at the Kanagawa Cancer Center. CMVR was defined as initiation of preemptive CMV therapy after pp65 antigenemia surveillance. All patients' lymphocyte subsets were monitored by flow cytometry at 180, 365, and 730 days post-transplant. The median follow-up period was 3.2 years (range, .8 to 9.6 years). CMVR occurred in 141 patients (57%) at a median of 45 days (range, 15 to 93). In patients without CMVR (CMVR-) versus those with CMVR (CMVR+), 5-year overall survival (OS), nonrelapse mortality (NRM), and cumulative incidence of relapse (CIR) were 79% versus 55% (P < .001), 3% versus 16% (P = .012), and 28% versus 38% (P = .09), respectively. CD8 T cell and CD3CD56 NK cell subset were higher in CMVR+ patients at day 100 post-transplant. Multivariate analysis showed that adverse factors for OS were represented by no remission, CMVR, and lower CD16CD57NK cell counts. Overall, a higher NK cell subset significantly contributed to a lower CIR. Among subgroups of CMVR+ patients, CD16CD57NK cells represented a favorable factor for OS, NRM, and CIR. CMVR was an adverse event after allo-SCT. NK cell reconstitution may contribute to improved outcomes, especially in CMVR+ subgroups. 10.1016/j.bbmt.2019.09.028
    A New Conditioning Regimen Can Significantly Promote Post-Transplant Immune Reconstitution and Improve the Outcome of Umbilical Cord Blood Transplantation for Patients. Yu Zheng-Ping,Ding Jia-Hua,Sun Ai-Ning,Chen Bao-An,Ge Zheng,Wu De-Pei Stem cells and development This study included data from 81 consecutively enrolled patients with hematological diseases who had been treated with unrelated umbilical cord blood transplantation (UCBT) between September 2014 and April 2019. All patients received intense conditioning regimens with combined fludarabine and high-dose cyclophosphamide (FC) before undergoing UCBT. Sixty-seven patients received a single UCBT, and 14 patients received a double UCBT. Fifty patients were pretreated with the fludarabine, busulfan, and cyclophosphamide (FBC) protocol, while 31 patients were treated with FC before transplantation. Graft-versus-host disease (GVHD) was prevented with cyclosporine A and mycophenolate mofetil administration. According to low-resolution, human leukocyte antigen (HLA) donor-recipient matching at six sites, 53 patients had 5-6 matches, while 28 patients had 4 matches. Seventy-eight patients (96.3%) achieved complete engraftment in this study. Thirty-six patients developed acute GVHD (aGVHD). The cumulative incidence of grade I-II aGVHD at day 100 posthematopoietic stem cell transplantation was 29.6%, and the cumulative incidence of grade III-IV aGVHD was 14.8%. At the end of the follow-up, 12 patients died due to treatment-related complications, and 4 died of disease relapse after transplantation. The transplant-related deaths were due to transplant-related infection (8 of 81), GVHD (2 of 81), and organ toxicity (2 of 81). The probability of overall survival (OS) was 80.2%. A higher dose of cyclophosphamide combined with fludarabine conditioning in UCBT was an effective curative method for treatment of hematologic disorders and could enhance the engraftment of umbilical cord blood stem cells, promote post-transplant immune reconstitution, and improve OS. 10.1089/scd.2019.0139
    An ISCT Stem Cell Engineering Committee Position Statement on Immune Reconstitution: the importance of predictable and modifiable milestones of immune reconstitution to transplant outcomes. Cytotherapy Allogeneic stem cell transplantation is a potentially curative therapy for some malignant and non-malignant disease. There have been substantial advances since the approaches first introduced in the 1970s, and the development of approaches to transplant with HLA incompatible or alternative donors has improved access to transplant for those without a fully matched donor. However, success is still limited by morbidity and mortality from toxicity and imperfect disease control. Here we review our emerging understanding of how reconstitution of effective immunity after allogeneic transplant can protect from these events and improve outcomes. We provide perspective on milestones of immune reconstitution that are easily measured and modifiable. 10.1016/j.jcyt.2021.09.011
    [Advances in newborn screening and immune system reconstitution of severe combined immunodeficiency]. Huang Shumin,Zhao Zhengyan Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences Severe combined immunodeficiency disease (SCID) is a group of rare congenital diseases characterized by severe deficiencies in T lymphocyte counts and/or function. The recurrent, persistent and severe infections are its clinical manifestations. Neonatal screening and immune system reconstruction would improve the prognosis of SCID children. Newborn screening programs based on T-cell receptor excision circles (TRECs) quantitative detection have been carried out in clinical practice, however, the methods still have some limitations. Other new methods such as mass spectrometry and T lymphocyte-specific biomarker assays are still under investigation. Hematopoietic stem cell transplantation and gene therapy are the two main methods for reconstructing immune function in SCID children. Through improving the success rate of transplantation and the long-term safety and stability of viral vectors, some achievements have been made by many centers already. However, large-scale prospective studies are needed for evaluation of the long-term efficacy. In this article, the recent progress in newborn screening and immune reconstitution of SCID is reviewed. 10.3785/j.issn.1008-9292.2019.08.01
    Clinical significance of T cell receptor excision circle (TREC) quantitation after allogenic HSCT. Blood research BACKGROUND:Hematopoietic stem cell transplantation (HSCT) is a well-established treatment modality for a variety of diseases. Immune reconstitution is an important event that determines outcomes. The immune recovery of T cells relies on peripheral expansion of mature graft cells, followed by differentiation of donor-derived hematopoietic stem cells. The formation of new T cells occurs in the thymus and as a byproduct, T cell receptor excision circles (TRECs) are released. Detection of TRECs by PCR is a reliable method for estimating the amount of newly formed T cells in the circulation and, indirectly, for estimating thymic function. The aim of this study was to determine the role of TREC quantitation in predicting outcomes of human leucocyte antigen (HLA) identical allogenic HSCT. METHODS:The study was conducted on 100 patients receiving allogenic HSCT from an HLA identical sibling. TREC quantification was done by real time PCR using a standard curve. RESULTS:TREC levels were inversely related to age (=0.005) and were significantly lower in patients with malignant diseases than in those with benign diseases (=0.038). TREC levels could predict relapse as an outcome but not graft versus host disease (GvHD) and infections. CONCLUSION:Age and nature of disease determine the TREC levels, which are related to relapse. 10.5045/br.2019.54.4.274
    Epigenetic programming of T cells impacts immune reconstitution in hematopoietic stem cell transplant recipients. Hardy Kristine,Smith Corey,Tu Wen Juan,McCuaig Robert,Panikkar Archana,Dasari Vijayendra,Wu Fan,Tey Siok-Keen,Hill Geoffrey R,Khanna Rajiv,Rao Sudha Blood advances Immune reconstitution following hematopoietic stem cell transplantation (HSCT) is critical in preventing harmful sequelae in recipients with cytomegalovirus (CMV) infection. To understand the molecular mechanisms underlying immune reconstitution kinetics, we profiled the transcriptome-chromatin accessibility landscape of CMV-specific CD8 T cells from HCST recipients with different immune reconstitution efficiencies. CMV-specific T cells from HSCT recipients with stable antiviral immunity expressed higher levels of interferon/defense response and cell cycle genes in an interconnected network involving , , , , and lower , increasing chromatin accessibility at the enhancer regions of immune and T-cell receptor signaling pathway genes. By contrast, the transcriptional and epigenomic signatures of CMV-specific T cells from HSCT recipients with unstable immune reconstitution showed commonalities with T-cell responses in other nonresolving chronic infections. These signatures included higher levels of EGR and KLF factors that, along with lower JARID2 expression, maintained higher accessibility at promoter and CpG-rich regions of genes associated with apoptosis. Furthermore, epigenetic targeting via inhibition of HDAC6 or JARID2 enhanced the transcription of genes associated with differential responses, suggesting that drugs targeting epigenomic modifiers may have therapeutic potential for enhancing immune reconstitution in HSCT recipients. Taken together, these analyses demonstrate that transcription factors and chromatin modulators create different chromatin accessibility landscapes in T cells of HSCT recipients that not only affect immediate gene expression but also differentially prime cells for responses to additional signals. Epigenetic therapy may be a promising strategy to promote immune reconstitution in HSCT recipients. 10.1182/bloodadvances.2018015909
    Delayed immune reconstitution after allogeneic transplantation increases the risks of mortality and chronic GVHD. Bejanyan Nelli,Brunstein Claudio G,Cao Qing,Lazaryan Aleksandr,Luo Xianghua,Curtsinger Julie,Mehta Rohtesh S,Warlick Erica,Cooley Sarah A,Blazar Bruce R,Miller Jeffrey S,Weisdorf Daniel,Wagner John E,Verneris Michael R Blood advances Slow immune reconstitution is a major obstacle to the successful use of allogeneic hematopoietic cell transplantation (allo-HCT). As matched sibling donor (MSD) allo-HCT is regarded as the gold standard, we evaluated the pace of immune reconstitution in 157 adult recipients of reduced-intensity conditioning followed by MSD peripheral blood HCT (n = 68) and compared these to recipients of umbilical cord blood (UCB; n = 89). At day 28, UCB recipients had fewer natural killer (NK) cells than MSD recipients, but thereafter, NK cell numbers (and their subsets) were higher in UCB recipients. During the first 6 months to 1 year after transplant, UCB recipients had slower T-cell subset recovery, with lower numbers of CD3, CD8, CD8 naive, CD4 naive, CD4 effector memory T, regulatory T, and CD3CD56 T cells than MSD recipients. Notably, B-cell numbers were higher in UCB recipients from day 60 to 1 year. Bacterial and viral infections were more frequent in UCB recipients, yet donor type had no influence on treatment-related mortality or survival. Considering all patients at day 28, lower numbers of total CD4 T cells and naive CD4 T cells were significantly associated with increased infection risk, treatment-related mortality, and chronic graft-versus-host disease (GVHD). Patients with these characteristics may benefit from enhanced or prolonged infection surveillance and prophylaxis as well as immune reconstitution-accelerating strategies. 10.1182/bloodadvances.2017014464
    Effect of Antihuman T Lymphocyte Globulin on Immune Recovery after Myeloablative Allogeneic Stem Cell Transplantation with Matched Unrelated Donors: Analysis of Immune Reconstitution in a Double-Blind Randomized Controlled Trial. Gooptu Mahasweta,Kim Haesook T,Chen Yi-Bin,Rybka Witold,Artz Andrew,Boyer Michael,Johnston Laura,McGuirk Joseph,Shea Thomas C,Jagasia Madan,Shaughnessy Paul J,Reynolds Carol G,Fields Marie,Alyea Edwin P,Ho Vincent T,Glavin Frank,Dipersio John F,Westervelt Peter,Ritz Jerome,Soiffer Robert J Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation We recently conducted a randomized double-blind study in which we demonstrated that moderate/severe chronic graft-versus-host disease (cGVHD) but not cGVHD-free survival was reduced in patients receiving anti-T lymphocyte globulin (ATLG) versus placebo. In a companion study we performed immunophenotypic analysis to determine the impact of ATLG on immune reconstitution (IR) and to correlate IR with clinical outcomes. The randomized study (n = 254) included patients (aged 18 to 65 years) who underwent myeloablative transplants for acute myeloid leukemia, myelodysplastic syndrome, or acute lymphoblastic leukemia from HLA-matched unrelated donors. Ninety-one patients consented for the companion IR study (ATLG = 44, placebo = 47). Blood samples were collected on days 30, 100, 180, and 360 after hematopoietic cell transplantation (HCT), and multiparameter flow cytometry was performed in a blinded fashion. Reconstitution of CD3 and CD4 T cells was delayed up to 6 months post-HCT in the ATLG arm, whereas absolute regulatory T cell (Treg) (CD425127-) numbers were lower only in the first 100 days. Analysis of the CD4 Treg and conventional T cells (Tconv) (CD425127) compartments showed a profound absence of naive Tregs and Tconv in the first 100 days post-HCT, with very slow recovery for 1 year. B cell and natural killer cell recovery were similar in each arm. Higher absolute counts of CD3, CD4, CD8 T, Tregs, and Tconv were associated with improved overall survival, progression-free survival, and nonrelapse mortality but not moderate/severe cGVHD. Although ATLG delays CD3 and CD4 T cell recovery post-transplant, it has a relative Treg sparing effect after the early post-HCT period, with possible implications for protection from cGVHD. ATLG severely compromises the generation of naive CD4 cells (Treg and Tconv), potentially affecting the diversity of the TCR repertoire and T cell responses against malignancy and infection. 10.1016/j.bbmt.2018.07.002
    Joint Modeling of Immune Reconstitution Post Haploidentical Stem Cell Transplantation in Pediatric Patients With Acute Leukemia Comparing CD34-Selected to CD3/CD19-Depleted Grafts in a Retrospective Multicenter Study. Salzmann-Manrique Emilia,Bremm Melanie,Huenecke Sabine,Stech Milena,Orth Andreas,Eyrich Matthias,Schulz Ansgar,Esser Ruth,Klingebiel Thomas,Bader Peter,Herrmann Eva,Koehl Ulrike Frontiers in immunology Rapid immune reconstitution (IR) following stem cell transplantation (SCT) is essential for a favorable outcome. The optimization of graft composition should not only enable a sufficient IR but also improve graft vs. leukemia/tumor effects, overcome infectious complications and, finally, improve patient survival. Especially in haploidentical SCT, the optimization of graft composition is controversial. Therefore, we analyzed the influence of graft manipulation on IR in 40 patients with acute leukemia in remission. We examined the cell recovery post haploidentical SCT in patients receiving a CD34-selected or CD3/CD19-depleted graft, considering the applied conditioning regimen. We used joint model analysis for overall survival (OS) and analyzed the dynamics of age-adjusted leukocytes; lymphocytes; monocytes; CD3, CD3CD4, and CD3CD8 T cells; natural killer (NK) cells; and B cells over the course of time after SCT. Lymphocytes, NK cells, and B cells expanded more rapidly after SCT with CD34-selected grafts ( = 0.036,  = 0.002, and  < 0.001, respectively). Contrarily, CD3CD4 helper T cells recovered delayer in the CD34 selected group ( = 0.026). Furthermore, reduced intensity conditioning facilitated faster immune recovery of lymphocytes and T cells and their subsets ( < 0.001). However, the immune recovery for NK cells and B cells was comparable for patients who received reduced-intensity or full preparative regimens. Dynamics of all cell types had a significant influence on OS, which did not differ between patients receiving CD34-selected and those receiving CD3/CD19-depleted grafts. In conclusion, cell reconstitution dynamics showed complex diversity with regard to the graft manufacturing procedure and conditioning regimen. 10.3389/fimmu.2018.01841
    Improved Overall Survival, Relapse-Free-Survival, and Less Graft-vs.-Host-Disease in Patients With High Immune Reconstitution of TCR Gamma Delta Cells 2 Months After Allogeneic Stem Cell Transplantation. Minculescu Lia,Marquart Hanne Vibeke,Ryder Lars Peter,Andersen Niels Smedegaard,Schjoedt Ida,Friis Lone Smidstrup,Kornblit Brian Thomas,Petersen Søren Lykke,Haastrup Eva,Fischer-Nielsen Anne,Reekie Joanne,Sengelov Henrik Frontiers in immunology T-cell receptor (TCR) γδ cells are perceived as innate-like effector cells with the possibility of mediating graft-vs. -tumor (GVT) without causing graft-vs.-host disease (GVHD) in the setting of hematopoietic allogeneic stem cell transplantation (HSCT). We conducted a prospective study to assess the clinical impact of TCR γδ cell immune reconstitution on overall survival, relapse-free-survival, relapse and GVHD. The impact of CD3, CD4, and CD8 T cells together with NK cells including subtypes were analyzed in parallel. A total of 108 patients with hematological malignancies transplanted with HLA-matched, T cell replete stem cell grafts were included for analyses of absolute concentrations of CD3, CD4, and CD8 positive T cells and NK cells together with a multi-color flow cytometry panel with staining for TCRαβ, TCRγδ, Vδ1, Vδ2, CD3, CD4, CD8, HLA-DR, CD196, CD45RO, CD45RA, CD16, CD56, CD337, and CD314 at 28, 56, 91, 180, and 365 days after transplantation. Immune reconstitution data including subsets and differentiation markers of T and NK cells during the first year after transplantation was provided. Patients with TCR γδ cell concentrations above the median value of 21 (0-416) × 10 cells/L 56 days after transplantation had significantly improved overall survival ( = 0.001) and relapse-free survival ( = 0.007) compared to patients with concentrations below this value. When day 56 cell subset concentrations were included as continuous variables, TCR γδ cells were the only T cell subsets with a significant impact on OS and RFS; the impact of TCR γδ cells remained statistically significant in multivariate analyses adjusted for pre-transplant risk factors. The risk of death from relapse was significantly decreased in patients with high concentrations of TCR γδ cells 56 days after transplantation ( = 0.003). Also, the risk of acute GVHD was significantly lower in patients with day 28 TCR γδ cell concentrations above the median of 18 × 10 cells/L compared to patients with low concentrations ( = 0.01). These results suggest a protective role of TCR γδ cells in relapse and GVHD and encourage further research in developing adaptive TCR γδ cell therapy for improving outcomes after HSCT. 10.3389/fimmu.2019.01997
    National Institutes of Health-Defined Chronic Graft-vs.-Host Disease in Pediatric Hematopoietic Stem Cell Transplantation Patients Correlates With Parameters of Long-Term Immune Reconstitution. Lawitschka Anita,Gueclue Ece Dila,Januszko Angela,Körmöczi Ulrike,Rottal Arno,Fritsch Gerhard,Bauer Dorothea,Peters Christina,Greinix Hildegard T,Pickl Winfried F,Kuzmina Zoya Frontiers in immunology Recent data revealed the importance of immune reconstitution (IR) for the evaluation of possible biomarkers in National Institutes of Health (NIH)-defined chronic graft-vs.-host disease (cGVHD) and its clinical aspects. In this large pediatric study ( = 146), we have analyzed whether cellular and humoral parameters of IR in the long-term follow-up (FU) with a special emphasis on B-cell reconstitution correlate with NIH-defined cGVHD criteria. HYPOTHESIS: we were especially interested in whether meaningful cGVHD biomarkers could be defined in a large pediatric cohort. We here demonstrate for the first time in a highly homogenous pediatric patient cohort that both cGVHD ( = 38) and its activity were associated with the perturbation of the B-cell compartment, including low frequencies of CD19CD27 memory B-cells and increased frequencies of circulating CD19CD21 B-cells, a well-known hyperactivated B-cell subset frequently found elevated in chronic infection and autoimmunity. Notably, resolution of cGVHD correlated with expansion of CD19CD27 memory B-cells and normalization of CD19CD21 B-cell frequencies. Moreover, we found that the severity of cGVHD had an impact on parameters of IR and that severe cGVHD was associated with increased CD19CD21 B-cell frequencies. When comparing the clinical characteristics of the active and non-active cGVHD patients (in detail at time of analyses), we found a correlation between activity and a higher overall severity of cGVHD, which means that in the active cGVHD patient group were more patients with a higher disease burden of cGVHD-despite similar risk profiles for cGVHD. Our data also provide solid evidence that the time point of analysis regarding both hematopoietic stem cell transplantation (HSCT) FU and cGVHD disease activity may be of critical importance for the detailed investigation of pediatric cohorts. Finally, we have proven that the differences in risk factors and patterns of IR, with cGVHD as its main confounding factor, between malignant and non-malignant diseases, are important to be considered in future studies aiming at identification of novel biomarkers for cGVHD. 10.3389/fimmu.2019.01879
    Impact of low-dose anti-thymocyte globulin on immune reconstitution after allogeneic hematopoietic cell transplantation. Ito Ayumu,Kitano Shigehisa,Tajima Kinuko,Kim Youngji,Tanaka Takashi,Inamoto Yoshihiro,Kim Sung-Won,Yamamoto Noboru,Fukuda Takahiro,Okamoto Shinichiro International journal of hematology How low-dose anti-thymocyte globulin (ATG) for prophylaxis of graft-versus-host disease (GVHD) influences immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HCT) remains incompletely understood. We prospectively enrolled 41 consecutive adult patients and conducted cytometry-based immunophenotyping for 12 months after allo-HCT. Rabbit ATG (Thymoglobulin) was administered at a median total dose of 1.75 mg/kg in 16 of the 41 patients. Compared with patients who did not receive ATG, those who did had a significantly smaller number of naïve T cells (especially CD4+ ) within three months after allo-HCT. No significant difference was observed between the two groups in the reconstitution of other T cells (effector, memory, Th1, Th2, Th17, Treg, and Tfh), B cells (transitional, naïve, memory, and plasmablast), NK cells (regulatory and cytolytic), or dendritic cells (myeloid and plasmacytoid). Patients with fewer CD4+ naïve T cells than the median count (7.60 cells/µL) at two months after allo-HCT developed chronic GVHD less frequently than those with CD4+ naïve T cells above the median count (2-year cumulative incidences were 0.31 and 0.53, respectively; p = 0.133). This pilot study suggests low-dose Thymoglobulin suppresses the recovery of naïve T cells after allo-HCT, which may contribute to a lower incidence of chronic GVHD. 10.1007/s12185-019-02756-1
    Early viral reactivation despite excellent immune reconstitution following haploidentical Bone marrow transplant with post-transplant cytoxan for sickle cell disease. Patel Dilan A,Dhedin Nathalie,Chen Heidi,Karnik Leena,Gatwood Katie,Culos Katie,Mohan Sanjay,Engelhardt Brian G,Kitko Carrie,Connelly Jim,Satyanarayana Gowri,Jagasia Madan,De La Fuente Josu,Kassim Adetola Transplant infectious disease : an official journal of the Transplantation Society BACKGROUND:Haploidentical bone marrow transplant (haplo-BMT) offers near universal donor availability as a curative modality for individuals with severe sickle cell disease (SCD). However, the required intense immunodepletion is associated with increased infectious complications. A paucity of data exists on immune reconstitution following haplo-BMT for SCD. METHODS:A multi-institution learning collaborative was developed in the context of a phase II clinical trial of a non-myeloablative, related haplo-BMT with post-transplant cyclophosphamide for SCD. We report results from a cohort of 23 patients for whom immune reconstitution data up to one year were available. RESULTS:Median age was 14.8 years. Out of 23, 18 participants received pre-conditioning with azathioprine, hydroxyurea, and hypertransfusions. 70% (16/23) of participants had multiple indications for haplo-BMT. We observed excellent immune reconstitution of CD4, CD8, CD19, and CD56 cellular subsets by 6 months post transplant. Engraftment rate and event-free survival in this cohort were 100% and 96%, respectively. 70% (16/23) of patients had at least one viral reactivation or infection, including CMV 35% (8/23), HHV-6 22% (5/23), and polyoma virus 17% (4/23), with no cases of post-transplant lymphoproliferative disease. CONCLUSION:Further prospective studies are needed to better characterize immune reconstitution and the immunologic basis for increased viral reactivation following haplo-BMT with post-transplant cyclophosphamide for SCD. 10.1111/tid.13222
    Humoral Immune Reconstitution Kinetics after Allogeneic Hematopoietic Stem Cell Transplantation in Children: A Maturation Block of IgM Memory B Cells May Lead to Impaired Antibody Immune Reconstitution. Abdel-Azim Hisham,Elshoury Amro,Mahadeo Kris M,Parkman Robertson,Kapoor Neena Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Although T cell immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been well studied, long-term B cell immune reconstitution remains less characterized. We evaluated humoral immune reconstitution among 71 pediatric allo-HSCT recipients. Although tetanus toxoid antibody levels were normal at 1 year after allo-HSCT, antipolysaccharide carbohydrate antibodies remained persistently low for up to 5 years. While naive B cell counts normalized by 6 months, IgM memory B cell deficiency persisted for up to 2 years (P = .01); switched memory B cell deficiency normalized by 1 year after allo-HSCT. CD4 T cell immune reconstitution correlated with that of switched memory B cells as early as 6 months after allo-HSCT (r = .55, P = .002) but did not correlate with IgM memory B cells at any time point after allo-HSCT. Taken together, this suggests that allo-HSCT recipients have impaired antibody immune reconstitution, mainly due to IgM memory B cell maturation block, compared with more prompt T cell-dependent switched memory cell immune reconstitution. We further explored other factors that might affect humoral immune reconstitution. The use of total body irradiation was associated with lower naive B cells counts at 6 months after HSCT (P = .04) and lower IgM (P = .008) and switched (P = .003) memory B cells up to 2 years. Allo-HSCT recipients with extensive chronic graft-versus-host disease had lower IgM memory B cell counts (P = .03) up to 2 years after allo-HSCT. The use of cord blood was associated with better naive (P = .01), IgM (P = .0005), and switched memory (P = .006) B cells immune reconstitution. These findings may inform future prophylaxis and treatment strategies regarding risk of overwhelming infection, graft-versus-host disease, and post-allogeneic HSCT revaccination. 10.1016/j.bbmt.2017.05.005
    Mass Cytometry for the Assessment of Immune Reconstitution After Hematopoietic Stem Cell Transplantation. Stern Lauren,McGuire Helen,Avdic Selmir,Rizzetto Simone,Fazekas de St Groth Barbara,Luciani Fabio,Slobedman Barry,Blyth Emily Frontiers in immunology Mass cytometry, or Cytometry by Time-Of-Flight, is a powerful new platform for high-dimensional single-cell analysis of the immune system. It enables the simultaneous measurement of over 40 markers on individual cells through the use of monoclonal antibodies conjugated to rare-earth heavy-metal isotopes. In contrast to the fluorochromes used in conventional flow cytometry, metal isotopes display minimal signal overlap when resolved by single-cell mass spectrometry. This review focuses on the potential of mass cytometry as a novel technology for studying immune reconstitution in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Reconstitution of a healthy donor-derived immune system after HSCT involves the coordinated regeneration of innate and adaptive immune cell subsets in the recipient. Mass cytometry presents an opportunity to investigate immune reconstitution post-HSCT from a systems-level perspective, by allowing the phenotypic and functional features of multiple cell populations to be assessed simultaneously. This review explores the current knowledge of immune reconstitution in HSCT recipients and highlights recent mass cytometry studies contributing to the field. 10.3389/fimmu.2018.01672
    Immune Reconstitution and Infection Patterns after Early Alemtuzumab and Reduced Intensity Transplantation for Nonmalignant Disorders in Pediatric Patients. Bhatt Sima T,Bednarski Jeffrey J,Berg Julia,Trinkaus Kathryn,Murray Lisa,Hayashi Robert,Schulz Ginny,Hente Monica,Grimley Michael,Chan Ka Wah,Kamani Naynesh,Jacobsohn David,Nieder Michael,Hale Gregory,Yu Lolie,Adams Roberta,Dalal Jignesh,Pulsipher Michael A,Haut Paul,Chaudhury Sonali,Davis Jeffrey,Jaroscak Jennifer,Andreansky Martin,Willert Jennifer,Shenoy Shalini Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Hematopoietic stem cell transplantation (HSCT) is a therapeutic option for many nonmalignant disorders (NMD) and is curative or prevents disease progression. Reduced-intensity conditioning (RIC) in HSCT for NMD may reduce regimen-related acute toxicities and late complications. Myeloablation is often replaced by immune suppression in RIC regimens to support donor engraftment. The pace of immune reconstitution after immune suppression by RIC regimens is influenced by agents used, donor source, and graft-versus-host disease prophylaxis/treatment. In a multicenter trial (NCT 00920972) of HSCT for NMD, a RIC regimen consisting of alemtuzumab, fludarabine, and melphalan was substituted for myeloablation. Alemtuzumab was administered early (days -21 to -19) to mitigate major lymphodepletion of the incoming graft and the risk of graft rejection. Immune reconstitution and infectious complications were prospectively monitored for 1-year post-HSCT. Seventy-one patients met inclusion criteria for this report and received marrow or peripheral blood stem cell transplants. Immune reconstitution and infections are reported for related donor (RD) and unrelated donor (URD) transplants at 3 time-points (100days, 6 months, and 1 year post-HSCT). Natural killer cell recovery was rapid, and numbers normalized in both cohorts by day +100. Mean CD3, CD4, and CD8 T-lymphocyte numbers normalized by 6 months after RD HSCT and by 1 year in the URD group. CD4 and CD8 T-lymphocyte counts were significantly higher in patients who received RD HSCT at 6 months and at 1 year, respectively, post-HSCT compared with patients who received URD HSCT. The pace of CD19 B-cell recovery was markedly different between RD and URD cohorts. Mean B-cell numbers were normal by day 100 after RD HSCT but took 1 year post-HSCT to normalize in the URD cohort. Despite these differences in immune reconstitution, the timing and nature of infections did not differ between the groups, presumably because of comparable T-lymphocyte recovery. Immune reconstitution occurred at a faster pace than in prior reports using RIC with T-cell depletion. The incidence of infections was similar for both cohorts and occurred most frequently in the first 100days post-HSCT. Viral and fungal infections occurred at a lower incidence in this cohort, with "early" alemtuzumab compared with regimens administering serotherapy in the peritransplantation period. Patients were susceptible to bacterial infections primarily in the first 100days irrespective of donor source and had no increase in mortality from the same. The overall mortality rate from infections was 1.4% at 1 year. Close monitoring and prophylaxis against bacterial infections in the first 100days post-HSCT is necessary but is followed by robust immune reconstitution, especially in the T-cell compartment. 10.1016/j.bbmt.2018.10.008
    Clinical T Cell Receptor Repertoire Deep Sequencing and Analysis: An Application to Monitor Immune Reconstitution Following Cord Blood Transplantation. Gkazi Athina Soragia,Margetts Ben K,Attenborough Teresa,Mhaldien Lana,Standing Joseph F,Oakes Theres,Heather James M,Booth John,Pasquet Marlene,Chiesa Robert,Veys Paul,Klein Nigel,Chain Benny,Callard Robin,Adams Stuart P Frontiers in immunology Spectratyping assays are well recognized as the clinical gold standard for assessing the T cell receptor (TCR) repertoire in haematopoietic stem cell transplant (HSCT) recipients. These assays use length distributions of the hyper variable complementarity-determining region 3 (CDR3) to characterize a patient's T cell immune reconstitution post-transplant. However, whilst useful, TCR spectratyping is notably limited by its resolution, with the technique unable to provide data on the individual clonotypes present in a sample. High-resolution clonotype data are necessary to provide quantitative clinical TCR assessments and to better understand clonotype dynamics during clinically relevant events such as viral infections or GvHD. In this study we developed and applied a CDR3 Next Generation Sequencing (NGS) methodology to assess the TCR repertoire in cord blood transplant (CBT) recipients. Using this, we obtained comprehensive TCR data from 16 CBT patients and 5 control cord samples at Great Ormond Street Hospital (GOSH). These were analyzed to provide a quantitative measurement of the TCR repertoire and its constituents in patients post-CBT. We were able to both recreate and quantify inferences typically drawn from spectratyping data. Additionally, we demonstrate that an NGS approach to TCR assessment can provide novel insights into the recovery of the immune system in these patients. We show that NGS can be used to accurately quantify TCR repertoire diversity and to provide valuable inference on clonotypes detected in a sample. We serially assessed the progress of T cell immune reconstitution demonstrating that there is dramatic variation in TCR diversity immediately following transplantation and that the dynamics of T cell immune reconstitution is perturbed by the presence of GvHD. These findings provide a proof of concept for the adoption of NGS TCR sequencing in clinical practice. 10.3389/fimmu.2018.02547
    Immune reconstitution after T-cell replete HLA-haploidentical transplantation. McCurdy Shannon R,Luznik Leo Seminars in hematology Impaired immune reconstitution has been one of the perceived limitations of alternative donor transplantation. However, modern transplantation platforms such as HLA-haploidentical transplantation with either post-transplantation cyclophosphamide or with anti-thymocyte globulin combined with intense immunosuppression may be associated with robust immune recovery as inferred by low rate of infectious mortality and post-transplantation lymphoproliferative disease. Here, we review the data on immune reconstitution including individual cell subsets, the effect of reconstitution on outcomes, and comparative studies using these commonly utilized T-cell replete HLA-haploidentical platforms. We find robust recovery of neutrophils, natural killer cells, CD8 T-cells, and B-cells, with delayed CD4 T-cell recovery comparable to that after HLA-matched transplantation. In addition, while viral reactivations and infections appear more common after HLA-haploidentical when compared with HLA-matched transplantation, infectious mortality remains low likely due to modern cytomegalovirus monitoring, preemptive treatment, as well as relative frequency of nonlethal viral infections like polyomavirus hominis 1 (BK virus). Higher graft cell doses also appear to be associated with faster recovery without concomitant increases in lethal graft-vs-host disease. Finally, despite rapid numerical return of natural killer cells post-transplant, phenotypically they retain immaturity markers till day 180 or more after transplantation, which suggests an avenue for future research to improve outcomes further. 10.1053/j.seminhematol.2019.03.005
    Use of Multivariate Immune Reconstitution Patterns to Describe Immune Reconstitution after Allogeneic Stem Cell Transplantation in Children. Mellgren Karin,Nierop Andreas F M,Abrahamsson Jonas Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation Immune reconstitution after hematopoietic stem cell transplantation (HSCT) is a complex process. Impacts of the reconstitution of different immune cells over time are complex and difficult to understand. New mathematical models are needed to better understand this process. In this study, we used principal component analysis to better analyze the process of immune reconstitution after HSCT. Forty-six consecutive patients receiving HSCT for malignant and nonmalignant disorders were included in the study. All patients were followed for at least 24 months after transplantation with regular blood sampling for analysis of lymphocyte subset numbers and function. Exponentially transformed lymphocyte subset counts and lymphocyte functional markers were analyzed to identify major trends in the reconstitution process. Using our multivariate model for mapping immune reconstitution after HSCT, we showed that dysfunctional reconstitution patterns precede severe complications, such as chronic graft-versus-host disease, relapse, and death. 10.1016/j.bbmt.2019.06.018
    Comparison of Immune Reconstitution After Allogeneic Versus Autologous Stem Cell Transplantation in 182 Pediatric Recipients. Wiegering Verena,Eyrich Matthias,Winkler Beate,Schlegel Paul G Journal of pediatric hematology/oncology Hematopoietic stem cell transplantation (HSCT) is a life-saving procedure for children with a variety of malignant and nonmalignant conditions. However, even if immune reconstitution after HSCT has been studied extensively, until now, data on the comparison of immune reconstitution after autologous versus allogeneic HSCT are scarce, but might provide important clinical implications. We examined immune reconstitution (T cells, B cells, and NK cells) at defined timepoints in 147 children who received 182 HSCTs. Differences in the time course of immune reconstitution were analyzed in autologous versus allogeneic HSCT. We identified a quicker immune reconstitution in the T-cell compartment, especially in the CD4 and naive subset after autologous HSCT, whereas recipients of allogeneic transplants showed a higher TCRgd proportion. B-cell reconstitution showed a delayed immune reconstitution after allogeneic HSCT in the first 2 years after HSCT. However, a reconstitution of all lymphocyte subsets after HSCT could be achieved in all patients. Children undergoing an HSCT show a different pattern of immune reconstitution in the allogeneic and autologous setting. This might influence the outcome and should affect the clinical handling of infectious prophylaxis and revaccinations. 10.1097/MPH.0000000000001340
    A prospective observational study of immune reconstitution following transplantation with post-transplant reduced-dose cyclophosphamide from HLA-haploidentical donors. Nakamae Hirohisa,Fujii Kazuki,Nanno Satoru,Okamura Hiroshi,Nakane Takahiko,Koh Hideo,Nakashima Yasuhiro,Nakamae Mika,Hirose Asao,Teshima Takanori,Hino Masayuki Transplant international : official journal of the European Society for Organ Transplantation Allogeneic hematopoietic cell transplantation (HCT) from HLA-haploidentical donors with post-transplantation high-dose cyclophosphamide (PT/Cy-haplo) now predominates worldwide. However, to our knowledge, no prospective study has compared immune reconstitution after PT/Cy-haplo with that after conventional HCT. The mechanism by which chronic graft-versus-host disease (GVHD) is inhibited by PT/Cy-haplo also remains unknown. We prospectively compared immune recovery patterns of lymphocyte subsets among four groups of adult patients with hematological disease who received HCT from either HLA-matched related or HLA-matched unrelated donors, cord blood transplantation, or reduced-dose PT/Cy-haplo. Counts of CD4+ T-cell subsets, CD8+ T-cell subsets, and NK cells on days 30 and 60 were often lower in PT/Cy-haplo than those in HLA-matched related HCT. The immune recovery pace in PT/Cy-haplo subsequently caught up with that of the other grafts. The regulatory T cells (Tregs) to conventional CD4+ T-cell (Tcon) ratio was significantly higher until day 90 in PT/Cy-haplo. In multivariate analysis, a higher Tregs-to-Tcon ratio on day 60 was significantly associated with a lower incidence of chronic GVHD (P < 0.01). The preservation of Tregs by PT/Cy in the early phase might have resulted in a lower incidence of chronic GVHD. 10.1111/tri.13494
    Immune Reconstitution Following TCRαβ/CD19-Depleted Hematopoietic Cell Transplantation for Hematologic Malignancy in Pediatric Patients. Arnold Danielle E,MacMath Derek,Seif Alix E,Heimall Jennifer R,Wang Yongping,Monos Dimitri,Grupp Stephan A,Bunin Nancy J Transplantation and cellular therapy TCRαβ/CD19-depleted HCT has been used with excellent outcomes in pediatric patients with hematologic malignancies, and several studies have demonstrated rapid immune reconstitution in the nonmalignant setting. However, immune recovery following TCRαβ/CD19-depleted hematopoietic cell transplantation (HCT) for malignancy remains incompletely elucidated. Furthermore, the majority of studies to date have used haploidentical and matched unrelated donors. Here we report results of immune reconstitution following TCRαβ/CD19-depleted HCT for hematologic malignancy in 51 pediatric patients with hematologic malignancies, the majority of whom received grafts from unrelated donors. Grafts were from matched unrelated (n = 20), mismatched unrelated (n = 20), and haploidentical (n = 11) donors. The median CD34 cell dose was 10.2 × 10/kg (range, 4.54 to 20 × 10/kg), and the median TCRαβ cell dose was 2.53 × 10/kg (range, 0 to 44.9 × 10/kg). Conditioning was myeloablative with either busulfan or total body irradiation, cyclophosphamide, and thiotepa. Thirty-three patients also received rabbit antithymocyte globulin. No prophylactic post-transplantation immune suppression was routinely given. Forty-three patients received rituximab on day +1 for recipient positive Epstein-Barr virus serology. Forty-nine patients (96%) engrafted with a median time to neutrophil recovery of 13 days (range, 8 to 30 days). Thirty-seven patients (73%) are alive at a median follow-up of 25 months (range, 6 to 50 months). Nine patients (18%) developed grade II-IV acute graft-versus-host disease (GVHD), and 5 patients (11%) developed extensive chronic GVHD. Twenty-six patients (51%) experienced viral reactivation. T cell reconstitution was rapid with significant numbers of CD3, CD4, and CD8 T cells present on first assessment at 4 months post-HCT, and significant numbers of naïve CD4 T cells were present by 8 months post-HCT. Chronic GVHD was associated with delayed T cell recovery; however, T cell reconstitution was not affected by underlying diagnosis, donor source, TCRαβ T cell dose, conditioning regimen, or use of antithymocyte globulin. B cell recovery mirrored T cell recovery, and i.v. Ig was discontinued at a median of 8 months (range, 4 to 22 months) post-HCT in patients alive and relapse-free at last follow-up. Immune reconstitution is rapid following TCRαβ/CD19-depleted HCT in pediatric patients with hematologic malignancies. Donor graft source, haploidentical or unrelated, did not affect immune reconstitution. Viral reactivation is common in the first 100 days post-HCT, indicating that improved T cell defense is needed in the early post-HCT period. 10.1016/j.jtct.2020.10.006
    Immune reconstitution after T-cell replete HLA haploidentical hematopoietic stem cell transplantation using high-dose post-transplant cyclophosphamide. Maeda Yoshinobu Journal of clinical and experimental hematopathology : JCEH As HLA haploidentical related donors are quickly available, HLA haploidentical hematopoietic stem cell transplantation (haploHSCT) using high-dose post-transplant cyclophosphamide (PTCy) is now widely used. Recent basic and clinical studies revealed the details of immune reconstitution after T-cell replete haploHSCT using PTCy. T cells and NK cells in the graft proliferate abundantly at day 3 post-haploHSCT, and the PTCy eliminates these proliferating cells. After ablation of proliferating mature cells, donor-derived NK cell reconstitution occurs after the second week; however, recovering NK cells remain functionally impaired for at least several months after haploHSCT. PTCy depletes proliferating cells, resulting in the preferential accumulation of Treg and CD4+ T cells, especially the memory stem T cell (T) phenotype. T capable of both self-renewal and differentiation into effector T cells may play an important role in the first month of immune reconstitution. Subsequently, de novo T cells progressively recover but their levels remain well below those of donor CD4+ T cells at the first year after haploHSCT. The phenotype of recovering T cells after HSCT is predominantly effector memory, whereas B cells are predominantly phenotypically naive throughout the first year after haploHSCT. B cell recovery depends on de novo generation and they are not detected until week 4 after haploHSCT. At week 5, recovering B cells mostly exhibit an unconventional transitional cell phenotype and the cell subset undergoes maturation. Recent advances in immune reconstitution have improved our understanding of the relationship between haploHSCT with PTCy and the clinical outcome. 10.3960/jslrt.20040
    Functional immune reconstitution early after allogeneic haematopoietic cell transplantation: A comparison of pre- and post-transplantation cytokine responses in stimulated whole blood. Gjaerde Lars Klingen,Brooks Patrick Terrence,Andersen Niels Smedegaard,Friis Lone Smidstrup,Kornblit Brian,Petersen Søren Lykke,Schjødt Ida,Nielsen Susanne Dam,Ostrowski Sisse Rye,Sengeløv Henrik Scandinavian journal of immunology We aimed to use a novel standardized whole-blood stimulation system to evaluate differences in the functional immune reconstitution in patients early after allogeneic haematopoietic cell transplantation (HCT). Between April and September 2018, 30 patients undergoing HCT had whole blood samples collected around day -21 (day 0 being the day of haematopoietic cell infusion) and day +28. Whole blood was transferred to TruCulture assays comprising prefilled incubation tubes with cell culture medium and a standardized stimulus. We used a panel of four stimuli (lipopolysaccharide, resiquimod, heat-killed Candida albicans and polyinosinic:polycytidylic acid) and a blank, designed to evaluate the function of critical extra- and intracellular immunological signalling pathways. For each stimulus, the cytokine response was assessed by the concentration of interferon-γ, interleukin (IL)-12p40, IL-10, IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-17A and tumour necrosis factor-α using a multiplex Luminex assay. Pre-HCT cytokine responses were globally decreased across several different stimuli. Despite patients receiving immunosuppressive prophylaxis at the time, post-HCT cytokine responses were higher and less intercorrelated than pre-HCT responses, also after adjusting for differences in the leukocyte differential counts. For the resiquimod and heat-killed Candida albicans stimuli, we identified a cluster of patients in whom post-HCT responses were lower than average across several cytokines, indicating a possible functional immune deficiency. Our findings suggest that the standardized whole blood stimulation system can be used to reveal heterogeneity in the in vitro cytokine responses to various stimuli after HCT. Larger studies are needed to address if the functional immune reconstitution after HCT can predict the risk of infections. 10.1111/sji.13042
    Immune Reconstitution in the Aging Host: Opportunities for Mechanism-Based Therapy in Allogeneic Hematopoietic Cell Transplantation. Lin Richard J,Elias Harold K,van den Brink Marcel R M Frontiers in immunology Older patients with hematologic malignancies are increasingly considered for allogeneic hematopoietic cell transplantation with encouraging outcomes. While aging-related thymic dysfunction remains a major obstacle to optimal and timely immune reconstitution post- transplantation, recent accumulating evidence has suggested that various aging hallmarks such as cellular senescence, inflamm-aging, and hematopoietic stem cell exhaustion, could also impact immune reconstitution post-transplantation in both thymic-dependent and independent manner. Here we review molecular and cellular aspects of immune senescence and immune rejuvenation related to allogeneic hematopoietic cell transplantation among older patients and discuss potential strategies for mechanism-based therapeutic intervention. 10.3389/fimmu.2021.674093
    Enhanced Immune Reconstitution of γδ T Cells after Allogeneic Stem Cell Transplantation Overcomes the Negative Impact of Pretransplantation Minimal Residual Disease-Positive Status in Patients with Acute Myelogenous Leukemia. Klyuchnikov Evgeny,Badbaran Anita,Massoud Radwan,Fritsche-Friedland Ulrike,Janson Dietlinde,Ayuk Francis,Wolschke Christine,Bacher Ulrike,Kröger Nicolaus Transplantation and cellular therapy Minimal/measurable residual disease (MRD) before allogeneic stem cell transplantation (allo-SCT) in patients with acute myelogenous leukemia (AML) is a poor risk factor for outcome. γδ T cells represent a unique minority lymphocyte population that is preferentially located in peripheral tissues, can recognize antigens in a non-MHC-restricted manner, and plays a "bridging" role between the innate and adaptive immune systems. In this study, we investigated a potential graft-versus-leukemia effect of γδ T cell reconstitution post-transplantation in AML patients with pretransplantation positive MRD status (MRD). MRD assessment was performed in 202 patients using multicolored flow cytometry ("different from normal" strategy); 100 patients were deemed MRD. Analysis for absolute concentrations of CD3, CD4+, CD8, natural killer, and γδ T cells were performed by flow cytometry according to an internal protocol at day +30 and +100 post-transplantation. Differences between categorical and continuous variables were determined using the chi-square and Student t test, respectively. The Mann-Whitney U test was used to compare medians of continuous variables. Spearman's correlation was used for nonparametric assessment of correlation between different cell subsets during immune reconstitution. Kaplan-Meier survival analysis and Cox regression analysis were used to investigate the associations between immune reconstitution and survival outcomes. Gray's analysis was used to compute incidences of relapse, nonrelapse mortality, and graft-versus-host disease (GVHD). The median follow-up of survivors was 28 months (range 3 to 59 months). Younger age (≤58 years) of recipient and donor (<30 years), sex mismatch, use of a matched donor, cytomegalovirus reactivation, and administration of antithymocyte globulin were associated with a faster γδ T cell reconstitution. In multivariable analysis for MRD patients, a higher than median level of γδ T cells on days +30 and +100 resulted in significantly improved leukemia-free survival (hazard ratio [HR], 0.42 [P = .007] and 0.42 [P = .011], respectively) and overall survival (HR, 0.44 [P = .038] and 0.33 [P = .009], respectively). Furthermore, a higher γδ T cell level on day +30 was associated with a significantly reduced risk of relapse (HR, 0.36; P = .019). No impact of γδ T cell level on relapse at days +30 and +100 could be seen in MRD-negative patients, and no correlation with occurrence of GVHD was observed. Our data indicate that enhanced immune reconstitution of γδ T cells post-transplantation may overcome the higher relapse risk of pretransplantation MRD status in patients with AML. 10.1016/j.jtct.2021.06.003
    [Correlation between immune reconstitution and chronic graft-versus-host disease after unrelated cord blood transplantation and sibling peripheral blood stem cell transplantation]. Wang J,Pan T Z,Huang P P,Sun Z M,Zhu H P Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi To explore the relationship between the reconstitution of immune cells in patients with hematological malignancies and the occurrence of chronic graft-versus-host disease (cGVHD) after treatment with unrelated cord blood transplantation (UCBT) and sibling peripheral blood stem cell transplantation (PBSCT) . A total of 124 patients undergoing allogenic hematopoietic stem cell transplantation (allo-HSCT) in the First Affiliated Hospital of University of Science and Technology of China from March 2018 to August 2019, including 96 patients with UCBT and 28 patients with PBSCT. Peripheral blood immune cells of patients with UCBT and PBSCT were detected at 1, 3, 6, 9, and 12 months after transplantation using flow cytometry, and both UCBT and PBSCT patients were divided into cGVHD and non-cGVHD groups based on whether cGVHD occurred to explore the correlation between the immune cells reconstitution of the two types of transplantation and cGVHD. ①The cumulative incidence of the moderate to severe cGVHD in the UCBT group was significantly lower than that in the PBSCT group[9.38% (95% 3.35%-15.02%) 28.57% (95% 9.72%-43.50%) , =0.008]; the 2-year cumulative incidence of cGVHD and moderate to severe cGVHD in the UCBT group was lower than that in the PBSCT group[15.60% (95% 9.20%-23.60%) 32.10% (95% 15.80%-49.70%) , =0.047; 10.40% (95% 5.30%-17.50%) 28.60% (95% 13.30%-46.00%) , =0.014]. ②The absolute counts of CD4(+)T cells in the UCBT group were higher than those in the PBSCT group at 6, 9, and 12 months after transplantation[59.00 (36.70-89.65) ×10(7)/L 31.40 (18.10-44.00) ×10(7)/L, <0.001; 71.30 (49.60-101.45) ×10(7)/L 41.60 (25.82-56.27) ×10(7)/L, <0.001; 83.00 (50.17-121.55) ×10(7)/L 44.85 (31.62-62.10) ×10(7)/L, <0.001]; the proportions of CD4(+)T cells in the UCBT group were always higher than those in the PBSCT group (<0.05) . The absolute counts and proportions of B cells in the PBSCT group were higher than those in the UCBT group at the first month after transplantation[0.70 (0.30-1.70) ×10(7)/L 0.10 (0-0.30) ×10(7)/L, <0.001; 0.45% (0.30%-2.20%) 0.20% (0.10%-0.40%) , =0.002]; the absolute counts and proportions of B cells in the UCBT group were higher than those in the PBSCT group at 9 and 12 months after transplantation[53.80 (28.00-103.20) ×10(7)/L 23.35 (5.07-35.00) ×10(7)/L, <0.001; 21.45 (11.80-30.45) % 9.00% (3.08%-16.73%) , <0.001. 66.70 (36.97-98.72) ×10(7)/L 20.85 (7.72-39.40) ×10(7)/L, <0.001; 22.20% (14.93%-29.68%) 8.75% (5.80%-18.93%) , <0.001]. The absolute counts and proportions of regulatory B (Breg) cells in the UCBT group were higher than those in the PBSCT group at 6, 9, and 12 months after transplantation[1.23 (0.38-3.52) ×10(7)/L 0.05 (0-0.84) ×10(7)/L, <0.001; 5.35% (1.90%-12.20%) 1.45% (0-7.78%) , =0.002. 2.25 (1.07-6.71) ×10(7)/L 0.12 (0-0.77) ×10(7)/L, <0.001; 6.25% (2.00%-12.33%) 0.80% (0-5.25%) , <0.001. 3.69 (0.83-8.66) ×10(7)/L 0.46 (0-0.93) ×10(7)/L, <0.001; 6.15% (1.63%-11.75%) 1.40% (0.18%-5.85%) , <0.001].The absolute counts and proportions of CD3(+)T cells, CD8(+)T cells, and Treg cells in the UCBT group were not significantly different from those in the PBSCT group. ③The absolute counts of B cells in the non-cGVHD group of UCBT patients were higher than those in the moderate to severe cGVHD group at 6 and 12 months after transplantation (=0.038, =0.043) ; the proportions of B cells in the non-cGVHD group were higher than those in the moderate to severe cGVHD group at 6 months after transplantation (=0.049) . The absolute counts of Breg cells in the non-cGVHD group of patients with UCBT were higher than those in the moderate to severe cGVHD group at 6, 9, and 12 months after transplantation (=0.006, =0.028, =0.050) ; the proportions of Breg cells in the non-cGVHD group were higher than those in the moderate to severe cGVHD group at 9 months after transplantation (=0.038) . ④The absolute counts and proportions of B and Breg cells in the non-cGVHD group of patients with PBSCT were not statistically different than those in the moderate to severe cGVHD group. In the process of immune cell reconstitution, the Breg cells in the UCBT group were higher than those in the PBSCT group, and the Breg cells in the non-cGVHD group of the two types of transplantation were always higher than those in the moderate to severe cGVHD group, indicating that Breg cells can reduce the occurrence of cGVHD, revealing the possible reason for the lower incidence of cGVHD in the UCBT group. 10.3760/cma.j.issn.0253-2727.2021.06.005
    Increased Infections and Delayed CD4 T Cell but Faster B Cell Immune Reconstitution after Post-Transplantation Cyclophosphamide Compared to Conventional GVHD Prophylaxis in Allogeneic Transplantation. Khimani Farhad,Ranspach Peter,Elmariah Hany,Kim Jongphil,Whiting Junmin,Nishihori Taiga,Locke Frederick L,Perez Perez Ariel,Dean Erin,Mishra Asmita,Perez Lia,Lazaryan Aleksandr,Jain Michael D,Nieder Michael,Liu Hein,Faramand Rawan,Hansen Doris,Alsina Melissa,Ochoa Leonel,Davila Marco,Anasetti Claudio,Pidala Joseph,Bejanyan Nelli Transplantation and cellular therapy Post-transplantation cyclophosphamide (PTCy) is being increasingly used for graft-versus-host disease (GVHD) prophylaxis after allogeneic hematopoietic cell transplantation (allo-HCT) across various donor types. However, immune reconstitution and infection incidence after PTCy-based versus conventional GVHD prophylaxis has not been well studied. We evaluated the infection density and immune reconstitution (ie, absolute CD4 T cell, CD8 T cell, natural killer cell, and B cell counts) at 3 months, 6 months, and 1 year post-HCT in 583 consecutive adult patients undergoing allo-HCT with myeloablative (n = 223) or reduced-intensity (n = 360) conditioning between 2012 and 2018. Haploidentical (haplo; n = 75) and 8/8 HLA-matched unrelated (MUD; n = 08) donor types were included. GVHD prophylaxis was PTCy-based in all haplo (n = 75) and in 38 MUD allo-HCT recipients, whereas tacrolimus/methotrexate (Tac/MTX) was used in 89 and Tac/Sirolimus (Tac/Sir) was used in 381 MUD allo-HCT recipients. Clinical outcomes, including infections, nonrelapse mortality (NRM), relapse, and overall survival (OS), were compared across the 4 treatment groups. The recovery of absolute total CD4 T-cell count was significantly lower in the haplo-PTCy and MUD-PTCy groups compared with the Tac/MTX and Tac/Sir groups throughout 1 year post-allo-HCT (P = .025). In contrast, CD19 B-cell counts at 6 months and thereafter were higher in the haplo-PTCy and MUD-PTCy groups compared with the Tac/MTX and Tac/Sir groups (P < .001). Total CD8 T cell and NK cell recovery was not significantly different among the groups. Infection density analysis showed a significantly higher frequency of total infections in the haplo-PTCy and MUD-PTCy groups compared with the Tac/MTX and Tac/Sir groups (5.0 and 5.0 vs 1.8 and 2.6 per 1000-person days; P < .01) within 1 year of allo-HCT. The cumulative incidence of cytomegalovirus reactivation/infection at 1 year post-allo-HCT was higher in the haplo-PTCy group (51%) compared with the MUD-PTCy (26%), Tac/MTX (26%), or Tac/Sir (13%) groups (P < .001). The incidence of BK, human herpesvirus 6, and other viruses were also higher in the PTCy-based groups. Overall, the treatment groups had similar 2 year NRM (P = .27) and OS (P = .78) outcomes. Our data show that PTCy-based GVHD prophylaxis is associated with delayed CD4 T cell but faster B cell immune reconstitution and a higher frequency of infections compared with conventional GVHD prophylaxis but has no impact on nonrelapse mortality or overall survival. 10.1016/j.jtct.2021.07.023
    Immune Reconstitution following High-Dose Chemotherapy and Autologous Stem Cell Transplantation with or without Pembrolizumab Maintenance Therapy in Patients with Lymphoma. Transplantation and cellular therapy Autologous stem cell transplantation (ASCT) is a standard of care for patients with chemosensitive, relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) and diffuse large B cell lymphoma (DLBCL). Whereas the clinical benefit of ASCT has traditionally been attributed solely to cytoreduction from intensive chemotherapy, ASCT has important immunogenic effects that may contribute to its antitumor efficacy and could provide a favorable immune environment for post-ASCT immune-based maintenance treatments. We previously reported clinical results of a phase II trial (ClinicalTrials.gov identifier NCT02362997) testing 8 doses of pembrolizumab maintenance therapy after ASCT for patients with R/R cHL or DLBCL. To clarify the impact of pembrolizumab on immune reconstitution, we compared the kinetics of peripheral blood immune cell recovery after ASCT for trial patients receiving pembrolizumab maintenance to those of a contemporaneous control cohort of similar patients undergoing ASCT without pembrolizumab maintenance. This study was conducted to characterize the impact of post-ASCT pembrolizumab maintenance therapy on immune reconstitution for patients with R/R DLBCL and cHL and to identify candidate biomarkers of efficacy and immune-related adverse events (irAEs). Peripheral blood (PB) mononuclear cell samples were prospectively collected at 1 to 18 months after ASCT and analyzed by flow cytometry using a panel of fluorophore-conjugated monoclonal antibodies to identify B cells, natural killer (NK) cells, and various dendritic cell (DC) and T cell subsets. A median of 5 (range, 1 to 8) post-ASCT PB samples were collected from 144 patients (59 in the pembrolizumab group and 85 in the control group). Clinical characteristics of the 2 cohorts were similar. Compared with cHL patients, DLBCL patients (all of whom received anti-CD20 monoclonal antibody therapy before ASCT) had delayed CD19 cell reconstitution that persisted for at least 18 months after ASCT. No other differences in immune reconstitution based on lymphoma subtype were observed. Post-ASCT pembrolizumab maintenance therapy was associated with an elevation in circulating DCs (driven by higher levels of plasmacytoid and immature DCs) that persisted for the duration of pembrolizumab treatment, along with a significant reduction in PD-1 T cells that persisted for 6 to 12 months after completion of pembrolizumab therapy. Despite the key role of T cells in mediating the effects of PD-1 blockade, pembrolizumab maintenance did not affect recovery of any T cell subsets. In an exploratory analysis, a higher baseline CD4 terminal effector memory cell count (defined as CD3CD4CD45RACD62L) was associated with inferior progression-free survival (PFS), but only among patients who received pembrolizumab maintenance (P = .003). As continuous variables, lower absolute levels of NK cells (P = .009), PD-1 CD4 T cells (P = .005), and PD-1 CD8 T cells (P = .005) before pembrolizumab initiation were each associated with a higher risk of grade 2+ irAEs. Our findings indicate that post-ACST pembrolizumab maintenance therapy is associated with a persistent elevation of circulating DCs, but its impact on the reconstitution of other immune cells in peripheral blood appears limited. Our study suggests that early features of post-ASCT immune reconstitution could be associated with PFS and the risk of irAE and warrant additional investigation. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. 10.1016/j.jtct.2021.10.010
    The impact of different doses of antithymocyte globulin conditioning on immune reconstitution upon hematopoietic stem cell transplantation. Li Yahan,Wang Mingyang,Fang Xiaosheng,Jiang Yujie,Sui Xiaohui,Li Ying,Liu Xin,Wang Xianghua,Lu Dongyue,Sun Xue,Xu Hongzhi,Wang Xin Transplant immunology INTRODUCTION:Anti-thymocyte globulin (ATG) is used prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) for graft-versus-host disease (GVHD) prophylaxis. Two different ATG doses (7.5 or 10 mg/kg) were evaluated in comparison with a group without ATG therapy. METHODS:We retrospectively analyzed 132 patients who were transplanted with HSCT without ATG (non-ATG), or who received 7.5 mg/kg ATG (ATG-7.5) or 10 mg/kg ATG (ATG-10) prior to transplantation. The immune cells (CD3CD4 T cells, CD3CD8 T cells, CD19 B cells and CD16CD56 NK cells) were examined in peripheral blood every three months post-HSCT for 12 months. RESULTS:Compared with non-ATG group, combined ATG-7.5/ATG-10 groups had significantly lower CD3CD4 T cells and higher CD3CD8 T cells at 3, 6, 9, 12 months post-HSCT; thus, displaying a lower CD4/CD8 ratio in the ATG groups compared to non-ATG group. The ratio of CD19 B cells was statistically lower (at 3rd month, p = .014; at 6th month, p = .025) in combined ATG-7.5/ATG-10 groups at 3 and 6 months post-HSCT, but not at 9 and 12 months after HSCT. The ratios of CD3CD4 T cells, CD3CD8 T cells, CD19 B cells and CD16CD56 NK cells were similar between the ATG-7.5 and ATG-10 groups at all examined time points. The overall survival (OS), progression-free survival (PFS), relapse and acute GVHD (aGVHD) were comparable among recipients without ATG therapy and with ATG-7.5 or/and ATG-10 therapies. Multivariate analysis revealed that immune cells ratios were not independent factors affecting prognosis. CONCLUSION:The ATG therapy at higher and lower doses led to a delayed reconstitution of T cells and the inversion of CD4/CD8 ratio for at least one year after HSCT. 10.1016/j.trim.2021.101486
    CMV Infection and CMV-Specific Immune Reconstitution Following Haploidentical Stem Cell Transplantation: An Update. Luo Xiao-Hua,Zhu Yan,Chen Yu-Ting,Shui Li-Ping,Liu Lin Frontiers in immunology Haploidentical stem cell transplantation (haploSCT) has advanced to a common procedure for treating patients with hematological malignancies and immunodeficiency diseases. However, cure is seriously hampered by cytomegalovirus (CMV) infections and delayed immune reconstitution for the majority of haploidentical transplant recipients compared to HLA-matched stem cell transplantation. Three major approaches, including T-cell depletion (TCD) using antithymocyte globulin for haploSCT ( TCD-haploSCT), TCD using CD34 + positive selection for haploSCT ( TCD-haploSCT), and T-cell replete haploSCT using posttransplant cyclophosphamide (PTCy-haploSCT), are currently used worldwide. We provide an update on CMV infection and CMV-specific immune recovery in this fast-evolving field. The progress made in cellular immunotherapy of CMV infection after haploSCT is also addressed. Groundwork has been prepared for the creation of personalized avenues to enhance immune reconstitution and decrease the incidence of CMV infection after haploSCT. 10.3389/fimmu.2021.732826