title: Clinical features of type 1 autoimmune hepatitis in adolescence and early adulthood.
abstract: OBJECTIVE
  The peak age of the presentation of autoimmune hepatitis (AIH) is between 40 years and 50 years. 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 </= 30 years (group 1) were compared with 79 patients aged between 40 years and 50 years (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.
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Miyake
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kobashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yasunaka
authors.forename: Fusao
authors.initials: F
authors.lastname: Ikeda
authors.forename: Akinobu
authors.initials: A
authors.lastname: Takaki
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Okamoto
authors.forename: Kouichi
authors.initials: K
authors.lastname: Takaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikeda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Makino
authors.forename: Kohsaku
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ando
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Yamamoto