Abstract:Aims/Background: The present investigation compared the histological features of the liver of chronic hepatitis C patients who are or are not coinfected with hepatitis G virus (HGV) to determine the histological and clinical characteristics of HGV infection. Subjects and Methods: This study included 194 patients with chronic hepatitis C who visited our institution between 1993 and 1995. Detection of serum HGV RNA was performed by nested reverse transcription-polymerase chain reaction. Scores were assigned to indicate the severity of each of the following features on the liver biopsy of a patient: inflammatory cell infiltration in the periportal, parenchymal, and portal area; fibrous stage; lymphoid aggregates in the portal area; portal sclerotic change; perivenular fibrosis; pericellular fibrosis; bile duct damage; bridging necrosis; and irregular regeneration of hepatocytes (IR). Results: HGV RNA was detected in the sera of 18 (9.3%) of the 194 patients. The histological features of the HGV RNA-positive patients show significantly more severe bile duct damage, perivenular fibrosis, pericellular fibrosis and IR than the liver of the HGV RNA-negative patients. The biochemical results in the two groups did not significantly differ. Conclusion: Our data suggest that chronic HGV coinfection worsens the histological features of liver disease.