Biochemical and virological response to interferon therapy in patients with chronic hepatitis C, co-infected with hepatitis G virus

It is still unclear whether hepatitis G virus (HGV) and hepatitis C virus ( HCV) co-infection influences the natural course of chronic HCV infection an d the response to interferon (IFN) therapy. In this study, we investigated the HGV RNA changes and responses to IFN therapy of HGV RNA-positive hepati tis C patients. The presence of HGV RNA in 264 patients who received IFN th erapy at our institute was examined using the nested reverse transcription- polymerase chain reaction with primers deduced from the 5' non-coding regio n (5'-NCR) of the HGV. We also analysed the nucleotide sequences of the 5'- NCR and HGV before and after IFN therapy. Twelve (4.5%) of the 264 patients with chronic hepatitis C were HGV RNA positive. Of these 12 patients, full information was available in nine. Of those nine, seven became HGV RNA neg ative during IFN therapy but in six of the seven a relapse occurred. HCV RN A was not detected 1 year after IFN therapy in six patients. The serum alan ine aminotransferase (ALT) levels of all the HCV RNA-negative patients post -treatment was within the normal range, irrespective of their HGV RNA statu s. Nucleotide sequences did not change after IFN therapy in any patient. He nce, we confirm that HGV is sensitive to IFN therapy but the liver damage c aused by HGV infection is very mild or does not modify the liver function t ests.