Detection of hepatitis G virus RNA in patients with hepatitis B, hepatitis C, and non-A-E hepatitis by RT-PCR using multiple primer sets.

Hepatitis G virus(HGV)/GB virus C(GBV-C) is a newly identified virus associated with human hepatitis. The preliminary prevalence studies of HGV infection in Japan were entirely based on the detection of HGV RNA by RT-PCR. However, the selection of the different primer sets in such assay may influence sensitivity of the test because of the extensive genetic heterogeneity of HGV, and influence the estimation of the prevalence of HGV. To address this potential problem, we designed two primer sets from well conserved domains in the 5'NC and NS5 regions of HGV genome, and tested them together with the NS3-derived primer set in RT-PCR for their ability to detect HGV RNA in serial dilution of synthetic viral RNA templates. Subsequently, we used these three primer sets to detect HGV RNA in the sera of 371 Japanese patients with hepatitis B, hepatitis C, and non-A-E hepatitis. The results indicated that the primer set derived from the 5'NC region appeared to be most effective in detecting HGV RNA. The results also showed that only two out of the 126 patients (1.6%) with non-A-E hepatitis were positive for HGV RNA although the RNA were detected more frequently in patients with hepatitis B (2/38; 5.3%) and hepatitis C (17/207; 8.2%), suggesting that HGV is not a common causative agent for non-A-E hepatitis in Japan.