Studies on Organ Specificity

Summary

Rabbits injected with homogenate or extract of pooled rabbit kidneys, emulsified with complete Freund's adjuvant, responded in most cases with the production of antibodies, as detected by gel diffusion and complement fixation methods. The antisera showed a high degree of tissue and species specificity, giving strong reactions with extracts of rabbit kidney and very weak reactions with extracts of kidney from other species and of other tissues of rabbit. In gel diffusion, there were three antigen-antibody systems. Comparison of various rabbit tissues revealed a prominent antigen which was kidney-specific, a second antigen which was also kidney-specific but a minor component, and a third antigen which was shared between kidney and other tissues.

All three antibodies were shown to be autoantibodies, indicating the existence, not only of kidney-specific autoantigens, but also of a non-tissue-specific autoantigen. Damage to kidney structures was suggested from the development of proteinuria in most of the rabbits and from the histologic examinations. The latter showed mild cellular proliferation in the glomeruli of some of the animals. It may well be that more severe tissue damage would have been detected if the kidneys had been examined at earlier stages during immunization.