Chronic hepatitis in chimpanzee carriers of hepatitis B virus: morphologic, immunologic, and viral DNA studies.

Years after infection with hepatitis B virus, chimpanzees may have manifestations of the carrier state as described in man. In addition to serologic evidence for persistent viral infection, percutaneous liver biopsy specimens showed hepatitis B virus surface antigen in the cytoplasm and hepatitis B virus core antigen in the nucleus. Four carrier animals had portal inflammatory reaction as seen in human chronic persistent hepatitis. Viral DNA was demonstrated in nucleic acid extracts of liver biopsy specimens by molecular hybridization to cloned plasmic pA01 containing hepatitis B virus DNA sequences. Although a viral molecule of length greater than the putative virus was identified, it did not appear to represent integration of viral DNA into the host genome. The chimpanzee model may serve as a means to study the mechanism of hepatitis B viral persistence and progression to chronic liver disease.