A study of hepatitis B virus DNA in situ hybridization for chronic active hepatitis.

Liver biopsies of 50 patients with chronic active hepatitis B were analysed immunohistochemically for HBcAg and HBsAg, and, by in situ hybridization, for hepatitis B virus (HBV) DNA. Double staining for manifesting HBV DNA and viral antigen simultaneously was also performed in some of them. The localization patterns of HBV DNA in hepatocytes could be classified into whole cytoplasmic, submembranous, nucleic and intermembranous types. The last type suggests that HBV DNA might be transmitted directly to the adjacent hepatocytes through the cell membranes. The double staining indicated that the majority of hepatocytes with high levels of HBV replication did not contain HBcAg of HBsAg. Conversely, most liver cells with strongly positive HBAg had low or negligible levels of viral replication. In addition, in a few cases HBV DNA could be found in the cytoplasm of bile ductule epithelia and sinusoidal endothelia.