Studies on the pathogenesis of experimental chronic active hepatitis in rabbits. I. Induction of the disease and protective effect of allogeneic liver specific proteins.

By long-term immunization intraperitoneally over 143 weeks with human liver specific proteins (HLP) together with complete Freund's adjuvant a chronic active hepatitis (CAH) was produced in rabbits, and the protective effect of allogeneic liver specific proteins (RLP) against the development of liver lesions was tested. The animals (white New Zealands) were divided into 6 groups. Immunization with HLP caused in all animals the development of CAH or liver cirrhosis, depending on the antigen dose. An autoimmunity against liver antigens, induced by HLP, persisted by immunization with RLP. The combined application of HLP and RLP (native and aggregate free, respectively) caused the development of histologically demonstrable liver lesions in only 13% of the animals. Underlying the pathogenesis of the experimental CAH is, according to the existing results, a cellular cytotoxicity. This concept is supported by the protective effect of RLP on cellular immune reactions against RLP and the induction of liver lesions. The importance of an antibody mediated cellular cytotoxicity for the pathogenesis of the experimental CAH has to be clarified by further experiments.