Hepatitis G virus/GB virus C infection in patients with chronic non-B, non-C hepatitis

A new virus named hepatitis G virus or GB virus C (HGV/GBV-C) was recently identified as a causative agent for acute and chronic hepatitis. In this study, we tested HGV/eGBV-C RNA in serum in addition to hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA to study the causative agents involved in chronic non-B, non-C hepatitis. Of the 1089 patients with histological evidence of chronic viral hepatitis, 25 (2.3%) were negative for both hepatitis B surface antigen and second generation HCV antibody in serum. The 25 patients diagnosed as having chronic non-B, non-C hepatitis, were investigated in this study. HGV/GBV-C a RNA was detected by nested reverse transcription polymerase chain reaction using primers in 5′-untranslated, and the nonstructural (NS) 3 and NS5 regions. Of the 25 patients with chronic non-B, non-C hepatitis, four (16%) were positive for HGV/GBV-C RNA, only one (4%) was positive for HBV DNA, and none were positive for HCV RNA. Of the four patients with HGV/GBV-C RNA, two histologically had mild fibrosis, and the remaining two had cirrhosis. One patient with cirrhosis also had hepatocellular carcinoma, HBV DNA was positive in this patient. All three patients with only the HGV/GBV-C infection had a mild histological grade. In conclusion, HGV/GBV-C infection was involved in 16% of Japanese patients with chronic non-B, non-C hepatitis. Chronic hepatitis G seemed to exhibit mild hepatitis activity.