Preoperative diagnosis of benign thyroid nodules with indeterminate cytology.
Alexander Erik K,Kennedy Giulia C,Baloch Zubair W,Cibas Edmund S,Chudova Darya,Diggans James,Friedman Lyssa,Kloos Richard T,LiVolsi Virginia A,Mandel Susan J,Raab Stephen S,Rosai Juan,Steward David L,Walsh P Sean,Wilde Jonathan I,Zeiger Martha A,Lanman Richard B,Haugen Bryan R
The New England journal of medicine
BACKGROUND:Approximately 15 to 30% of thyroid nodules evaluated by means of fine-needle aspiration are not clearly benign or malignant. Patients with cytologically indeterminate nodules are often referred for diagnostic surgery, though most of these nodules prove to be benign. A novel diagnostic test that measures the expression of 167 genes has shown promise in improving preoperative risk assessment. METHODS:We performed a 19-month, prospective, multicenter validation study involving 49 clinical sites, 3789 patients, and 4812 fine-needle aspirates from thyroid nodules 1 cm or larger that required evaluation. We obtained 577 cytologically indeterminate aspirates, 413 of which had corresponding histopathological specimens from excised lesions. Results of a central, blinded histopathological review served as the reference standard. After inclusion criteria were met, a gene-expression classifier was used to test 265 indeterminate nodules in this analysis, and its performance was assessed. RESULTS:Of the 265 indeterminate nodules, 85 were malignant. The gene-expression classifier correctly identified 78 of the 85 nodules as suspicious (92% sensitivity; 95% confidence interval [CI], 84 to 97), with a specificity of 52% (95% CI, 44 to 59). The negative predictive values for "atypia (or follicular lesion) of undetermined clinical significance," "follicular neoplasm or lesion suspicious for follicular neoplasm," or "suspicious cytologic findings" were 95%, 94%, and 85%, respectively. Analysis of 7 aspirates with false negative results revealed that 6 had a paucity of thyroid follicular cells, suggesting insufficient sampling of the nodule. CONCLUSIONS:These data suggest consideration of a more conservative approach for most patients with thyroid nodules that are cytologically indeterminate on fine-needle aspiration and benign according to gene-expression classifier results. (Funded by Veracyte.).
Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy.
Smith Terry J,Janssen Joseph A M J L
Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.
Thyroid replacement therapy, thyroid stimulating hormone concentrations, and long term health outcomes in patients with hypothyroidism: longitudinal study.
Thayakaran Rasiah,Adderley Nicola J,Sainsbury Christopher,Torlinska Barbara,Boelaert Kristien,Šumilo Dana,Price Malcolm,Thomas G Neil,Toulis Konstantinos A,Nirantharakumar Krishnarajah
BMJ (Clinical research ed.)
OBJECTIVE:To explore whether thyroid stimulating hormone (TSH) concentration in patients with a diagnosis of hypothyroidism is associated with increased all cause mortality and a higher risk of cardiovascular disease and fractures. DESIGN:Retrospective cohort study. SETTING:The Health Improvement Network (THIN), a database of electronic patient records from UK primary care. PARTICIPANTS:Adult patients with incident hypothyroidism from 1 January 1995 to 31 December 2017. EXPOSURE:TSH concentration in patients with hypothyroidism. MAIN OUTCOME MEASURES:Ischaemic heart disease, heart failure, stroke/transient ischaemic attack, atrial fibrillation, any fractures, fragility fractures, and mortality. Longitudinal TSH measurements from diagnosis to outcomes, study end, or loss to follow-up were collected. An extended Cox proportional hazards model with TSH considered as a time varying covariate was fitted for each outcome. RESULTS:162 369 patients with hypothyroidism and 863 072 TSH measurements were included in the analysis. Compared with the reference TSH category (2-2.5 mIU/L), risk of ischaemic heart disease and heart failure increased at high TSH concentrations (>10 mIU/L) (hazard ratio 1.18 (95% confidence interval 1.02 to 1.38; P=0.03) and 1.42 (1.21 to 1.67; P<0.001), respectively). A protective effect for heart failure was seen at low TSH concentrations (hazard ratio 0.79 (0.64 to 0.99; P=0.04) for TSH <0.1 mIU/L and 0.76 (0.62 to 0.92; P=0.006) for 0.1-0.4 mIU/L). Increased mortality was observed in both the lowest and highest TSH categories (hazard ratio 1.18 (1.08 to 1.28; P<0.001), 1.29 (1.22 to 1.36; P<0.001), and 2.21 (2.07 to 2.36; P<0.001) for TSH <0.1 mIU/L, 4-10 mIU/L, and >10 mIU/L. An increase in the risk of fragility fractures was observed in patients in the highest TSH category (>10 mIU/L) (hazard ratio 1.15 (1.01 to 1.31; P=0.03)). CONCLUSIONS:In patients with a diagnosis of hypothyroidism, no evidence was found to suggest a clinically meaningful difference in the pattern of long term health outcomes (all cause mortality, atrial fibrillation, ischaemic heart disease, heart failure, stroke/transient ischaemic attack, fractures) when TSH concentrations were within recommended normal limits. Evidence was found for adverse health outcomes when TSH concentration is outside this range, particularly above the upper reference value.
Repeat thyroid function tests for healthy older people are not needed.
Cook Rob,Fortescue-Webb Duncan,Taft Rachel,
BMJ (Clinical research ed.)
The studyRoberts L, McCahon D, Johnson O, Haque MS, Parle J, Hobbs FR. Stability of thyroid function in older adults: the Birmingham Elderly Thyroid Study. Published on 28 August 2018 2018;68:e718-26.This study was funded by the National Institute for Health Research School for Primary Care Research (SPCR).To read the full NIHR Signal, go to: https://discover.dc.nihr.ac.uk/content/signal-000703/repeat-thyroid-function-tests-for-healthy-older-people-are-not-needed.
Regeneration of Thyroid Function by Transplantation of Differentiated Pluripotent Stem Cells.
Kurmann Anita A,Serra Maria,Hawkins Finn,Rankin Scott A,Mori Munemasa,Astapova Inna,Ullas Soumya,Lin Sui,Bilodeau Melanie,Rossant Janet,Jean Jyh C,Ikonomou Laertis,Deterding Robin R,Shannon John M,Zorn Aaron M,Hollenberg Anthony N,Kotton Darrell N
Cell stem cell
Differentiation of functional thyroid epithelia from pluripotent stem cells (PSCs) holds the potential for application in regenerative medicine. However, progress toward this goal is hampered by incomplete understanding of the signaling pathways needed for directed differentiation without forced overexpression of exogenous transgenes. Here we use mouse PSCs to identify key conserved roles for BMP and FGF signaling in regulating thyroid lineage specification from foregut endoderm in mouse and Xenopus. Thyroid progenitors derived from mouse PSCs can be matured into thyroid follicular organoids that provide functional secretion of thyroid hormones in vivo and rescue hypothyroid mice after transplantation. Moreover, by stimulating the same pathways, we were also able to derive human thyroid progenitors from normal and disease-specific iPSCs generated from patients with hypothyroidism resulting from NKX2-1 haploinsufficiency. Our studies have therefore uncovered the regulatory mechanisms that underlie early thyroid organogenesis and provide a significant step toward cell-based regenerative therapy for hypothyroidism.
Effect of Levothyroxine on Miscarriage Among Women With Normal Thyroid Function and Thyroid Autoimmunity Undergoing In Vitro Fertilization and Embryo Transfer: A Randomized Clinical Trial.
Wang Haining,Gao Hongwei,Chi Hongbin,Zeng Lin,Xiao Wenhua,Wang Yanrong,Li Rong,Liu Ping,Wang Chen,Tian Qing,Zhou Zehong,Yang Jin,Liu Ye,Wei Rui,Mol Ben Willem J,Hong Tianpei,Qiao Jie
Importance:Presence of thyroid autoantibodies in women with normal thyroid function is associated with increased risk of miscarriage. Whether levothyroxine treatment improves pregnancy outcomes among women undergoing in vitro fertilization and embryo transfer (IVF-ET) is unknown. Objective:To determine the effect of levothyroxine on miscarriage among women undergoing IVF-ET who had normal thyroid function and tested positive for thyroid autoantibodies. Design, Setting, and Participants:An open-label, randomized clinical trial involving 600 women who tested positive for the antithyroperoxidase antibody and were being treated for infertility at Peking University Third Hospital from September 2012 to March 2017. Interventions:The intervention group (n = 300) received either a 25-μg/d or 50-μg/d dose of levothyroxine at study initiation that was titrated according to the level of thyroid-stimulating hormone during pregnancy. The women in the control group (n = 300) did not receive levothyroxine. All participants received the same IVF-ET and follow-up protocols. Main Outcomes and Measures:The primary outcome was the miscarriage rate (pregnancy loss before 28 weeks of gestation, which was calculated among women who became pregnant). The secondary outcomes were clinical intrauterine pregnancy rate (fetal cardiac activity seen at sonography observation on the 30th day after the embryo transfer), and live-birth rate (at least 1 live birth after 28 weeks of gestation). Results:Among the 600 women (mean [SD] age, 31.6 [3.8] years) randomized in this trial, 567 women (94.5%) underwent IVF-ET and 565 (94.2%) completed the study. Miscarriage rates were 10.3% (11 of 107) in the intervention group and 10.6% (12 of 113) in the control group, with the absolute rate difference (RD) of -0.34% (95% CI, -8.65% to 8.12%) over the 4.5-year study period. Clinical intrauterine pregnancy rates were 35.7% (107 of 300) in the intervention group and 37.7% (113 of 300) in the control group, with an absolute RD of -2.00% (95% CI, -9.65% to 5.69%). Live-birth rates were 31.7% (95 of 300) in the intervention group and 32.3% (97 of 300) in the control group, with an absolute RD of -0.67% (95% CI, -8.09% to 6.77%). Conclusions and Relevance:Among women in China who had intact thyroid function and tested positive for antithyroperoxidase antibodies and were undergoing IVF-ET, treatment with levothyroxine, compared with no levothyroxine treatment, did not reduce miscarriage rates or increase live-birth rates. Trial Registration:Chinese Clinical Trial Registry: ChiCTR-TRC-13004097.
NADPH oxidases: new actors in thyroid cancer?
Ameziane-El-Hassani Rabii,Schlumberger Martin,Dupuy Corinne
Nature reviews. Endocrinology
Hydrogen peroxide (H2O2) is a crucial substrate for thyroid peroxidase, a key enzyme involved in thyroid hormone synthesis. However, as a potent oxidant, H2O2 might also be responsible for the high level of oxidative DNA damage observed in thyroid tissues, such as DNA base lesions and strand breakages, which promote chromosomal instability and contribute to the development of tumours. Although the role of H2O2 in thyroid hormone synthesis is well established, its precise mechanisms of action in pathological processes are still under investigation. The NADPH oxidase/dual oxidase family are the only oxidoreductases whose primary function is to produce reactive oxygen species. As such, the function and expression of these enzymes are tightly regulated. Thyrocytes express dual oxidase 2, which produces most of the H2O2 for thyroid hormone synthesis. Thyrocytes also express dual oxidase 1 and NADPH oxidase 4, but the roles of these enzymes are still unknown. Here, we review the structure, expression, localization and function of these enzymes. We focus on their potential role in thyroid cancer, which is characterized by increased expression of these enzymes.
Thyroid Function Within the Normal Range, Subclinical Hypothyroidism, and the Risk of Atrial Fibrillation.
Baumgartner Christine,da Costa Bruno R,Collet Tinh-Hai,Feller Martin,Floriani Carmen,Bauer Douglas C,Cappola Anne R,Heckbert Susan R,Ceresini Graziano,Gussekloo Jacobijn,den Elzen Wendy P J,Peeters Robin P,Luben Robert,Völzke Henry,Dörr Marcus,Walsh John P,Bremner Alexandra,Iacoviello Massimo,Macfarlane Peter,Heeringa Jan,Stott David J,Westendorp Rudi G J,Khaw Kay-Tee,Magnani Jared W,Aujesky Drahomir,Rodondi Nicolas,
BACKGROUND:Atrial fibrillation (AF) is a highly prevalent disorder leading to heart failure, stroke, and death. Enhanced understanding of modifiable risk factors may yield opportunities for prevention. The risk of AF is increased in subclinical hyperthyroidism, but it is uncertain whether variations in thyroid function within the normal range or subclinical hypothyroidism are also associated with AF. METHODS:We conducted a systematic review and obtained individual participant data from prospective cohort studies that measured thyroid function at baseline and assessed incident AF. Studies were identified from MEDLINE and EMBASE databases from inception to July 27, 2016. The euthyroid state was defined as thyroid-stimulating hormone (TSH) 0.45 to 4.49 mIU/L, and subclinical hypothyroidism as TSH 4.5 to 19.9 mIU/L with free thyroxine (fT4) levels within reference range. The association of TSH levels in the euthyroid and subclinical hypothyroid range with incident AF was examined by using Cox proportional hazards models. In euthyroid participants, we additionally examined the association between fT4 levels and incident AF. RESULTS:Of 30 085 participants from 11 cohorts (278 955 person-years of follow-up), 1958 (6.5%) had subclinical hypothyroidism and 2574 individuals (8.6%) developed AF during follow-up. TSH at baseline was not significantly associated with incident AF in euthyroid participants or those with subclinical hypothyroidism. Higher fT4 levels at baseline in euthyroid individuals were associated with increased AF risk in age- and sex-adjusted analyses (hazard ratio, 1.45; 95% confidence interval, 1.26-1.66, for the highest quartile versus the lowest quartile of fT4; for trend ≤0.001 across quartiles). Estimates did not substantially differ after further adjustment for preexisting cardiovascular disease. CONCLUSIONS:In euthyroid individuals, higher circulating fT4 levels, but not TSH levels, are associated with increased risk of incident AF.
Central hypothyroidism - a neglected thyroid disorder.
Beck-Peccoz Paolo,Rodari Giulia,Giavoli Claudia,Lania Andrea
Nature reviews. Endocrinology
Central hypothyroidism is a rare and heterogeneous disorder that is characterized by a defect in thyroid hormone secretion in an otherwise normal thyroid gland due to insufficient stimulation by TSH. The disease results from the abnormal function of the pituitary gland, the hypothalamus, or both. Moreover, central hypothyroidism can be isolated or combined with other pituitary hormone deficiencies, which are mostly acquired and are rarely congenital. The clinical manifestations of central hypothyroidism are usually milder than those observed in primary hypothyroidism. Obtaining a positive diagnosis for central hypothyroidism can be difficult from both a clinical and a biochemical perspective. The diagnosis of central hypothyroidism is based on low circulating levels of free T in the presence of low to normal TSH concentrations. The correct diagnosis of both acquired (also termed sporadic) and congenital (also termed genetic) central hypothyroidism can be hindered by methodological interference in free T or TSH measurements; routine utilization of total T or T measurements; concurrent systemic illness that is characterized by low levels of free T and normal TSH concentrations; the use of the sole TSH-reflex strategy, which is the measurement of the sole level of TSH, without free T, if levels of TSH are in the normal range; and the diagnosis of congenital hypothyroidism based on TSH analysis without the concomitant measurement of serum levels of T. In this Review, we discuss current knowledge of the causes of central hypothyroidism, emphasizing possible pitfalls in the diagnosis and treatment of this disorder.
Clinical aspects of thyroid function during ageing.
Chaker Layal,Cappola Anne R,Mooijaart Simon P,Peeters Robin P
The lancet. Diabetes & endocrinology
Globally, populations are ageing at a rapid rate. The increase in the number of older citizens is accompanied by an increased prevalence of thyroid dysfunction, one of the most common disorders in older people. However, the diagnosis of thyroid dysfunction in older people is hindered by several factors, including the scarcity of thyroid dysfunction symptoms in older people. We describe the physiological changes in thyroid function that occur with increasing age, focusing on literature regarding changes in thyroid function test results in older populations. We also discuss treatment considerations for clinical and subclinical thyroid dysfunction according to international guidelines for older people. Finally, we discuss the relationship between variations in thyroid function and common diseases of old age including cardiovascular disease, osteoporosis, cognitive impairment, and frailty and suggest directions for future research.
Follicular cell-derived thyroid cancer.
Dralle Henning,Machens Andreas,Basa Johanna,Fatourechi Vahab,Franceschi Silvia,Hay Ian D,Nikiforov Yuri E,Pacini Furio,Pasieka Janice L,Sherman Steven I
Nature reviews. Disease primers
Follicular cell-derived thyroid cancers are derived from the follicular cells in the thyroid gland, which secrete the iodine-containing thyroid hormones. Follicular cell-derived thyroid cancers can be classified into papillary thyroid cancer (80-85%), follicular thyroid cancer (10-15%), poorly differentiated thyroid cancer (<2%) and undifferentiated (anaplastic) thyroid cancer (<2%), and these have an excellent prognosis with the exception of undifferentiated thyroid cancer. The advent and expansion of advanced diagnostic techniques has driven and continues to drive the epidemic of occult papillary thyroid cancer, owing to overdiagnosis of clinically irrelevant nodules. This transformation of the thyroid cancer landscape at molecular and clinical levels calls for the modification of management strategies towards personalized medicine based on individual risk assessment to deliver the most effective but least aggressive treatment. In thyroid cancer surgery, for instance, injuries to structures outside the thyroid gland, such as the recurrent laryngeal nerve in 2-5% of surgeries or the parathyroid glands in 5-10% of surgeries, negatively affect quality of life more than loss of the expendable thyroid gland. Furthermore, the risks associated with radioiodine ablation may outweigh the risks of persistent or recurrent disease and disease-specific mortality. Improvement in the health-related quality of life of survivors of follicular cell-derived thyroid cancer, which is decreased despite the generally favourable outcome, hinges on early tumour detection and minimization of treatment-related sequelae. Future opportunities include more widespread adoption of molecular and clinical risk stratification and identification of actionable targets for individualized therapies.
Interconnection between circadian clocks and thyroid function.
Ikegami Keisuke,Refetoff Samuel,Van Cauter Eve,Yoshimura Takashi
Nature reviews. Endocrinology
Circadian rhythmicity is an approximately 24-h cell-autonomous period driven by transcription-translation feedback loops of specific genes, which are referred to as 'circadian clock genes'. In mammals, the central circadian pacemaker, which is located in the hypothalamic suprachiasmatic nucleus, controls peripheral circadian clocks. The circadian system regulates virtually all physiological processes, which are further modulated by changes in the external environment, such as light exposure and the timing of food intake. Chronic circadian disruption caused by shift work, travel across time zones or irregular sleep-wake cycles has long-term consequences for our health and is an important lifestyle factor that contributes to the risk of obesity, type 2 diabetes mellitus and cancer. Although the hypothalamic-pituitary-thyroid axis is under the control of the circadian clock via the suprachiasmatic nucleus pacemaker, daily TSH secretion profiles are disrupted in some patients with hypothyroidism and hyperthyroidism. Disruption of circadian rhythms has been recognized as a perturbation of the endocrine system and of cell cycle progression. Expression profiles of circadian clock genes are abnormal in well-differentiated thyroid cancer but not in the benign nodules or a healthy thyroid. Therefore, the characterization of the thyroid clock machinery might improve the preoperative diagnosis of thyroid cancer.
Structure-inherent targeting of near-infrared fluorophores for parathyroid and thyroid gland imaging.
Hyun Hoon,Park Min Ho,Owens Eric A,Wada Hideyuki,Henary Maged,Handgraaf Henricus J M,Vahrmeijer Alexander L,Frangioni John V,Choi Hak Soo
The typical method for creating targeted contrast agents requires covalent conjugation of separate targeting and fluorophore domains. In this study, we demonstrate that it is possible to create near-infrared (NIR) fluorophores with different tissue specificities driven by their inherent chemical structures. Thus, a single compact molecule performs both targeting and imaging. We use this strategy to solve a major problem in head and neck surgery: the identification and preservation of parathyroid and thyroid glands. We synthesized 700-nm and 800-nm halogenated fluorophores that show high uptake into these glands after a single intravenous (IV) injection of 0.06 mg kg(-1) in a pig. By using a dual-channel NIR imaging system, we observed-in real time and with high sensitivity-the unambiguous distinction of parathyroid and thyroid glands simultaneously in the context of blood and surrounding soft tissue. This novel technology lays a foundation for performing head and neck surgery with increased precision and efficiency along with potentially lower morbidity, and it provides a general strategy for developing targeted NIR fluorophores.
The role of thyroglobulin in thyroid hormonogenesis.
Citterio Cintia E,Targovnik Héctor M,Arvan Peter
Nature reviews. Endocrinology
In humans, the thyroid hormones T and T are synthesized in the thyroid gland in a process that crucially involves the iodoglycoprotein thyroglobulin. The overall structure of thyroglobulin is conserved in all vertebrates. Upon thyroglobulin delivery from thyrocytes to the follicular lumen of the thyroid gland via the secretory pathway, multiple tyrosine residues can become iodinated to form mono-iodotyrosine (MIT) and/or di-iodotyrosine (DIT); however, selective tyrosine residues lead to preferential formation of T and T at distinct sites. T formation involves oxidative coupling between two DIT side chains, and de novo T formation involves coupling between an MIT donor and a DIT acceptor. Thyroid hormone synthesis is stimulated by TSH activating its receptor (TSHR), which upregulates the activity of many thyroid gene products involved in hormonogenesis. Additionally, TSH regulates post-translational changes in thyroglobulin that selectively enhance its capacity for T formation - this process is important in iodide deficiency and in Graves disease. 167 different mutations, many of which are newly discovered, are now known to exist in TG (encoding human thyroglobulin) that can lead to defective thyroid hormone synthesis, resulting in congenital hypothyroidism.
Thyroid surgery for differentiated thyroid cancer - recent advances and future directions.
Wang Tracy S,Sosa Julie Ann
Nature reviews. Endocrinology
Population-based studies have demonstrated that an increasing number of incidental thyroid nodules are being identified. The corresponding increase in thyroid-based diagnostic procedures, such as fine-needle aspiration biopsy, has in part led to an increase in the diagnoses of thyroid cancers and to more thyroid surgeries being performed. Small papillary thyroid cancers account for most of this increase in diagnoses. These cancers are considered to be low risk because of the excellent patient outcomes, with a 5-year disease-specific survival of >98%. As a result, controversy remains regarding the optimal management of newly diagnosed differentiated thyroid cancer, as the complications related to thyroidectomy (primarily recurrent laryngeal nerve injury and hypoparathyroidism) have considerable effects on patient quality of life. This Review highlights current debates, including undertaking active surveillance versus thyroid surgery for papillary thyroid microcarcinoma, the extent of thyroid surgery and lymphadenectomy for low-risk differentiated thyroid cancer, and the use of molecular testing to guide decision-making about whether surgery is required and the extent of the initial operation. This Review includes a discussion of current consensus guideline recommendations regarding these topics in patients with differentiated thyroid cancer. Additionally, innovative thyroidectomy techniques (including robotic and transoral approaches) are discussed, with an emphasis on patient preferences around decision-making and outcomes following thyroidectomy.