RESUMO
The in situ hybridization of HBV DNA with biotinylated probe in formalin-fixed and paraffin-embedded liver tissue sections was performed and the localization and morphology of HBV DNA in various types of chronic liver diseases was observed. 25 cases out of 75 (asymptomatic HBsAg carriers 4/21, chronic persistent hepatitis 2/7, chronic active hepatitis 10/21, liver cirrhosis 0/3, subacute severe hepatitis 4/11 and hepatocellular carcinoma with cirrhosis 5/12) were HBV DNA positive(33.33%). HBV DNA in hepatocytes was demonstrated as numerous coarse grains in cytoplasm and occasionally a few grains in individual nucleus. The distribution of the HBV DNA positive hepatocytes in the sections was in 3 forms, i.e., the diffuse type(Type I, 4/25, 16%), the focal type(Type II, 20/25, 80%), aud the scattered type (Type III, 1/25, 4%). The HBV DNA grained in the cytoplasm might be condensed (Type a)or sparsed(Type b)depsnding on the number of HBV DNA grains. The different distribution patterns and the amount of HBV DNA might be a reflection of the replication activity and the state of infectivity of HBV. HBV DNA positive hepatocytes were found only in the tissue adjacent to the cancer cells in cases of hepatocellular carcinoma with cirrhosis.