Autoimmune hepatitis and its variant syndromes

Abstract
Three types of AIH have been proposed based on immunoserological findings but only two types have mutually exclusive autoantibodies and different clinical profiles.9 Type 1 AIH is the most common form of the disease worldwide and is associated with antinuclear antibodies (ANA) and/or smooth muscle antibodies (SMA). It affects all age groups and is associated with human leucocyte antigen (HLA) DR3 (DRB1*0301) and DR4 (DRB1*0401) in Caucasoid Northern European and North American patients.10 11 DRB1*0301 andDRB1*0401 influence disease expression and behaviour as well as susceptibility. Caucasoid patients with type 1 AIH and DRB1*0301 are younger, and have a higher frequency of treatment failure,12 relapse after drug withdrawal,13 and requirement for liver transplantation than patients with other alleles.14 In contrast, patients with DRB1*0401 are typically older, frequently have concurrent autoimmune diseases, and respond better to corticosteroids than counterparts withDRB1*0301.15