GB virus C/hepatitis G virus infection in hemodialysis patients: determination of seroprevalence by a four-antigen recombinant immunoblot assay.

GB Virus C/Hepatitis G Virus (GBV-C/HGV) was identified recently and only two assays, consisting of a single recombinant protein, have been described for determination of the seroprevalence of this virus. An immunoblot assay was devised, which contains four recombinant GBV-C/HGV proteins. In this study, serum samples from 154 patients on maintenance hemodialysis were examined to assess the rate of seroreactivity against GBV-C/HGV. All sera were tested for the presence of antibodies by an in-house recombinant immunoblot assay, for GBV-C/HGV viremia by RT-PCR, and for HCV infection by PCR and by serological assays. Antibody reactivity against GBV-C/HGV was detected in 20.8% (n = 32) and viremia was found in 6.5% (n = 10) of the patients. In no case were viremia and GBV-C/HGV antibodies detected in parallel. HCV infection was observed in 15.6% (n = 24) by RT-PCR. In 20 of these patients, HCV antibodies were detected by enzyme immuno assay (EIA) and immunoblot assay. However, four of the HCV PCR-positive patients were negative by both serological tests. Only two patients were viremic for GBV-C/HGV and HCV in parallel. It is concluded that antibody reactivity against GBV-C/HGV is common among patients on maintenance hemodialysis. In contrast to HCV, parallel occurrence of GBV-C/HGV viremia and GBV-C/HGV seroreactivity was not observed. This suggests that GBV-C/HGV infection might be self-limiting.