Clinical features of type 1 autoimmune hepatitis in adolescence and early adulthood

Aim: The peak age of the presentation of autoimmune hepatitis (AIH) is between 40years and 50years. Elderly patients have been reported to have higher frequencies of concurrent thyroid or rheumatic diseases and histological cirrhosis and a lower occurrence of treatment failure. In this study, we assessed the clinical features of Japanese type 1 AIH in adolescence and early adulthood. Methods: Fifteen patients aged ≤ 30years (group 1) were compared with 79 patients aged between 40 years and 50years (group 2). Results: At presentation, patients aged ≤ 30 years accounted for 9% of the study population. Although frequencies of extrahepatic concurrent autoimmune diseases were similar between groups 1 and 2, a tendency toward a lower frequency of concurrent autoimmune thyroiditis was shown in group 1 (0 vs. 18%, P = 0.08). Group 1 had a lower frequency of human leukocyte antigen DR4 (27 vs. 78%, P = 0.002), and histological acute hepatitis was shown more frequently in group 1 (27 vs. 4%, P = 0.002). However, there were no differences in frequencies of the normalization of serum transaminase levels after the introduction of corticosteroid treatment or relapse after the normalization of serum transaminase levels between the two groups. Conclusions: Japanese type 1 AIH patients in adolescence and early adulthood respond well to corticosteroid treatment. However, they may frequently show atypical features, and the diagnosis of type 1 AIH in adolescence and early adulthood may be difficult and should be made carefully.