A histopathological study on localization of hepatitis C virus RNA in liver of chronic hepatitis C

By in situ hybridization (ISH) method using digoxygenin (DIG)-labeled RNA probe, we proved the localization and replication of hepatitis C virus (HCV) RNA not only in the hepatocytes but also in the lymphocytes of the 52 liver tissues of chronic hepatitis C. We classified the staining patterns into four groups. The pattern of signal distribution significantly correlated with serum alanine aminotransferase (ALT) level, quantity of serum HCV RNA just before liver biopsy, histological grade of inflammatory activity, and stage of fibrosis by Spearman rank correlation. Moreover, we investigated the relation between the signals in the hepatocytes or lymphocytes and the effectiveness of interferon (IFN) therapy. Therefore, we suggest that ISH is a useful tool to evaluate the activity of chronic hepatitis C associated with serological and histopathological changes and is an important marker to assess the effectiveness of IFN treatment.