PATHOLOGY OF VIRAL-HEPATITIS TYPE-A AND TYPE-B IN CHIMPANZEES - COMPARISON

Abstract

The histologic manifestations in the livers of chimpanzees inoculated with hepatitis A and B virus were compared and correlated with biochemical, serologic, and virologic observations. Both viruses cause alterations similar to those in human hepatitis, but the lesions, particularly the hepatocellular necrosis, are milder. Hepatitis Type A in chimpanzees is a disease of short incubation period and duration. The hepatocytic alterations are mainly restricted to the periportal areas, and the parenchymal changes are less severe than the portal inflammation. The lesions correlated well with biochemical changes and the presence of virus in the liver and the stool. Experimental Type B hepatitis has a long incubation period and longer duration, involves the entire lobular parenchyma, and is more severe in the lobular centers while protal inflammation is less conspicuous. Biochemical alterations and presence of virus in the liver correlate with these lesions, and the antibody response is similar to that seem in man. The chimpanzee is a useful model for studying the pathogenesis of viral hepatitis; additional study of serial morphologic events may contribute to the understanding of the clinical differences between hepatitis Type A and Type B.