HBCAG AND HBSAG EXPRESSION IN DUCTULAR CELLS IN CHRONIC HEPATITIS-B

The possible involvement of bile duct epithelium (BDE) in chronic hepa titis B was examined by immunohistochemical investigation of HBcAg and HBsAg expression in biliary cells in 47 liver biopsies with both vira l antigens detectable in hepatocytes. HBcAg- and HBsAg-positive cells were identified in nine and five cases, respectively, in atypical and occasionally in typical ductules in cases of acute excacerbation, chro nic active hepatitis and active cirrhosis. Atypical ductules were usua lly located in areas of periportal fibrosis and in cirrhotic septa. Li ver cell plates expressing viral markers and undergoing ductular trans formation (positive reaction of hepatocytes to BDE-specific, wide-spec trum keratin) were also observed in acinar zone 1, at the periphery an d within parenchymal nodules in a number of cases. The presence of bot h viral antigens in atypical ductules in cases of advanced chronic liv er disease most probably expresses the persistence of the virus in cel ls deriving from biliary metaplasia of infected hepatocytes. However, the detection of the Virus in a few typical ductules is indicative of a direct viral infection. According to these findings, ductular cells seem to serve as a suitable host for HBV, their genotype permitting vi ral replication and antigen production.