Etiopathogenesis of autoimmune hepatitis. Floreani Annarosa,Restrepo-Jiménez Paula,Secchi Maria Francesca,De Martin Sara,Leung Patrick S C,Krawitt Edward,Bowlus Christopher L,Gershwin M Eric,Anaya Juan-Manuel Journal of autoimmunity Autoimmune hepatitis is a chronic inflammatory liver disease characterized by hypergammaglobulinemia, the presence of autoantibodies, and inflammation within the liver, including lymphocytic infiltrates and interface hepatitis. Autoimmune hepatitis shows a female predominance and can present at any age and in any ethnicity. The disease is thought to be a consequence of a break of immune tolerance leading to an autoimmune process that induces liver injury. The self-attack is triggered by T-helper cell-mediated liver autoantigen recognition and B-cell production of autoantibodies, and is sustained by impaired regulatory T cells number and function. Superimposed on a genetic predisposition, infections and environmental factors have been studied as triggering factors for the disease. Allelic variants in the HLA locus have been associated with susceptibility; associations with single nucleotide polymorphisms within non-HLA genes have also been assessed. Several factors have been described as triggers of autoimmune responses in predisposed individuals, including infections, alcohol, vitamin D deficiency, and an altered composition of the intestinal microbiome. Importantly, drugs and herbal agents may trigger classical autoimmune hepatitis, or may induce a liver disease with autoimmune features. Interactions between female hormones and genetic factors have been hypothesized to play a role in autoimmunity, although the exact role for these factors has not been fully established. Herein we present a review of the etiology of autoimmune hepatitis including de novo autoimmune hepatitis post-liver transplantation as well as animal models for its study. 10.1016/j.jaut.2018.10.020

Hepatotoxicity of immune checkpoint inhibitors: a histology study of seven cases in comparison with autoimmune hepatitis and idiosyncratic drug-induced liver injury. Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc The adverse effects of immune checkpoint inhibitors in various organs may be attributed to immune-mediated processes triggered by disrupted self-tolerance; however, it remains unclear whether they are similar or dissimilar to classic organ-specific autoimmune diseases. The present study aimed to compare clinicopathologic features between checkpoint inhibitor-induced liver injury and acutely presenting autoimmune hepatitis or idiosyncratic drug-induced liver injury. Seven patients treated with nivolumab (n = 5) or ipilimumab (n = 2) presented with liver dysfunction a median of 41 days (range 21-120) after the initiation of immunotherapy. All patients had elevated liver enzymes, whereas hyper-bilirubinemia was less common. None of the patients had antinuclear antibodies or IgG elevations. Stopping the immunotherapy and additional immunosuppression with corticosteroids normalized or decreased liver enzymes in all patients treated. Histologically, all biopsies showed predominantly lobular hepatitis with milder portal inflammation. Centrilobular confluent necrosis and plasmacytosis were observed in a single case, and were markedly less common and milder than those in autoimmune hepatitis (p = 0.017 and p < 0.001, respectively). Bile duct injury, micro-abscesses, and extramedullary hematopoiesis were also found in one case each. Immunostaining revealed the presence of large numbers of CD3+ and CD8+ lymphocytes, whereas CD20+ B cells and CD4+ T cells were fewer in checkpoint inhibitor-induced liver injury than in autoimmune hepatitis or drug-induced liver injury. In conclusion, liver injury caused by cancer immunotherapy shares some features with injury of autoimmune hepatitis; however, there are obvious differences between the two conditions. Checkpoint inhibitor-induced liver injury may represent an immune-mediated, less zone-selective hepatocyte necrosis not requiring the strong activation of helper T cells and immunoglobulin production. 10.1038/s41379-018-0013-y