Lack of evidence for hepatitis G virus replication in the livers of patients coinfected with hepatitis C and G viruses.

The pathogenic implications of hepatitis G virus (HGV) infection are still unclear. We searched for the presence of HGV RNA and HCV RNA sequences in liver and serum samples from 10 patients with chronic liver disease, 9 of whom were coinfected with HCV. All livers were negative for the presence of the HGV RNA minus strand and only six were positive for the presence of the positive strand, albeit at low levels. In striking contrast, the HCV RNA positive strand was detectable in the liver samples from all nine HCV-positive patients in titers ranging from 10(2) to 10(8) genomic eq/microg of RNA, and the negative HCV RNA strand was present in all but two of these patients. However, the positive-strand RNA titers in serum for the two viruses had similar ranges. These findings imply that the liver is not the primary replication site for HGV, at least in the population of HCV/HGV-coinfected patients. Absence of replication in liver tissue may explain the reported lack of influence of HGV coinfection on the course of chronic hepatitis C.