GB virus C infection in patients with chronic hepatitis B and C before and after liver transplantation

Recently, a novel virus, tentatively designated GB virus C (GBV-C) was identified in patients with hepatitis, The frequency of this novel virus infection was therefore investigated in 58 patients with chronic hepatitis B virus (HBV) infection and in 74 patients with chronic hepatitis C virus (HCV) infection who had received orthotopic liver transplantation (OLT) because of decompensated liver cirrhosis, Before OLT, GBV-C sequences were found by reverse transcription nested polymerase chain reaction with primers derived from the helicase-like region in six (10%) of the HBV- and in six (8%) of the HCV-infected patients, Specificity of the polymerase chain reaction products was confirmed in eight of them by direct sequencing, Pretransplant GBV-C viremia was associated with posttransplant viremia in 75% of patients. The comparison of GBV-C nucleotide and amino acid sequences within the helicase-like region revealed that pre- and posttransplant sequences differed only in 0-7 nucleotide exchanges, and with the exception of one, all of them were silent mutations, After OLT, 29% of the HBV-infected and 12% of the HCV-infected patients became GBV-C positive, indicating a high rate of ''de novo'' GBV-C infection, By correlating the GBV-C status with the frequency of the occurrence of graft hepatitis in both groups of patients, it became evident that posttransplant GBV-C viremia did not increase the risk for this clinical condition, However, we found a significantly higher percentage of hepatocellular carcinoma in patients with pre-OLT GBV-C/HCV coinfection compared with patients with HCV infection alone (5/6 vs, 16/68; P < 0.01).