Autoimmune hepatitis: from immunopathogenesis to diagnostic and therapeutic innovation.

PURPOSE OF REVIEW: To understand the pathogenesis of autoimmune hepatitis (AIH) and the accuracy of diagnosis and treatment options that have improved lately. We summarize the latest research.

RECENT FINDINGS: Concerning pathogenesis of AIH, different groups have identified pieces of the puzzle that fit together well: An altered microbiome in the gut results in a proinflammatory response in the liver. This response is built by type II natural killer cells and CD4 T cells with an inflammatory phenotype and marked tumor necrosis factor production. When looking specifically at autoantigenic CD4 T cells, these have a B-helper phenotype on transcriptomic analysis. This explains not only elevation of immunoglobulins in AIH, but also mechanistically the effect of anti-B-cell substances in treatment. Diagnosis is now facilitated by an improved diagnostic score for AIH also recognizing modern techniques for autoantibody detection. Treatment in the future will increasingly be focused on reducing dosage and duration of steroid exposition. In addition, B-cell-targeted treatments have been evaluated with considerable success.

SUMMARY: Research in the past 18 months has improved the understanding of pathogenesis and thereby opened a number of possible treatment options. In addition, steroid use is cautioned by the recent findings.