Objective    To investigate the influence of gender on clinical characteristics in Chinese Han patients with type 1 autoimmune hepatitis.     Methods    As much as 113 Chinese patients diagnosed with definite AIH

who underwent liver biopsy between 2002 and 2009

and had frozen serum samples and clinical data available from the time of biopsy

were selected for this study. The presence of anti-nuclear antibodies (ANA)

smooth muscle antibodies (SMA) and liverkidney microsome type 1 (anti-LKM1) were measured by indirect immunofluorescence assay. All of the liver biopsies were reviewed in a blinded manner by the same expert pathologist. The charts were extensively reviewed for demographic and liver features obtained at the time of the biopsy. Of the 113 patients

26 were male AIH patients.     Results    Median age at cirrhosis onset was 60.62 years old in men and 47.17 years old in women (t=2.876

P=0.007). Positivity for ANA

ASMA and anti-LKM1 did not differ between the 2 groups. There was no significant difference in clinical manifestations at presentation. Our analysis indicated that no histopathological class of AIH was predominant in both males and females. Interestingly

the serum immunoglobulin G levels were higher in the female AIH patients compared to the male AIH group (21.86±9.12 vs 17.49±8.58 g/L

t=2.017

P=0.046). In addition

whilst the mean levels of serum aspartate aminotrans ferase

bilirubin and albumin were markedly altered（P0.05）

they were comparable between both AIH men and women.     Conclusion    Women with AIH-1 appear to have a younger age of cirrhosis onset

which may relate to repeated prevalence of liver inflammation.