Pathologic changes in the liver and kidney produced by immunization with intestinal antigens

Rabbits were immunized with intestinal antigens derived from rabbits, guinea pigs, and germfree rats. Inflammatory changes throughout the portal tracts of the liver were found in 55% (16 of 29) of the immunized rabbits. Interstitial nephritis was present in 7 of 23 rabbits evaluated. These changes did not occur when nonintestinal antigens were used for immunization. Antigen shared by liver, kidney, duodenum, ileum, and colon were found in each of the species used for immunization. An immune response to the antigen shared by the various tissues may be a factor in the pathogenesis of disease in this experimental system. In man, chronic active hepatitis and interstitial nephritis are found in association with inflammatory bowel disease. A similar mechanism of pathogenesis may be a factor in these extraintestinal manifestations of inflammatory bowel disease in man.