Hepatitis G virus infection in Japanese haemophiliacs

The recently identified hepatitis G virus (HGV) (also known as GB virus-C) has been considered as a blood-transmissible agent. As many haemophiliacs have risk factors for infectious agents, to clarify the frequency of HGV infection is important. HGV-RNA was investigated in 77 Japanese haemophiliacs who had been treated with nonvirus-inactivated concentrates derived from pooled plasma. Detection of HGV-RNA was performed with a nested RT-PCR that recognizes the 5'-NCR of the HGV genome. HGV-RNA was detected in 19 (24.7%), including four (21.0%) infected with HGV alone, 12 (63.2%) co-infected with HCV and three (15.8%) who were HBV carriers. The patients infected with HGV alone showed a normal ALT level of 18.7 ± 4.1 IU L(-1) . Most (36/37, 97.3%) of the patients with abnormal ALT levels had HCV-RNA. Patients infected with HCV alone or co-infected with HCV and HGV showed higher ALT levels of 108.8 ± 90.2 IU L(-1) (n= 39) and 67.6 ± 62.6 IU L(-1) (n= 11), respectively. However, there was no significant difference (P= 0.16) in ALT levels between HCV infection alone and HCV/HGV co-infection. On the other hand, four of the patients who could be followed over 10 years showed HGV-RNA persistently. In two who underwent liver biopsy, the histological evidence showed no definitive fibrotic and necro-inflammatory changes. These results indicate that HGV infection has frequently occurred in haemophiliacs. It is possible that HGV infection does not cause aggressive hepatitis with elevated ALT levels, and that co-infection with HGV may not aggravate hepatitis caused by HCV.