Autoimmune hepatitis type 1 without evidence of hepatitis G virus infection

Hepatitis G virus (HGV) RNA was measured in sera from 60 patients satisfying the international diagnostic criteria of definite autoimmune hepatitis type 1 using a reverse transcription and polymerase chain reaction with primers of the putative NS5 region of the HGV genome. Five patients had a history of blood transfusion. Of the 60 patients, 55 (92%) were confirmed as having human leukocyte antigen (HLA) DR4 or DR2 which are genetic markers for susceptibility to autoimmune hepatitis in Japanese. None of the 60 patients had any serum markers suggesting hepatitis B virus infection and 5 (8%) had evidence of on-going hepatitis C virus infection. No patients had HGV RNA in serum. The absence of active HGV infection in this cohort suggests that HGV does not play a casual role in the development of autoimmune hepatitis in Japan.