Kidney-specific allo- and autoantibodies in the alloantibody response to rat kidney: the use of kidney homogenate as a target for serological analysis.

LEW anti-DA kidney and DA anti-LEW kidney sera were assayed using an indirect 125I anti-immunoglobulin-binding assay with kidney homogenate as target. This allowed the full spectrum of antibodies to be analysed since the tissue used for immunization was the same as that used as the target in the serological analysis. It was found that around 80% of the LEW anti-DA kidney serum was directed at kidney-specific antigens, approximately half at a kidney-specific alloantigen, and half at a kidney-specific autoantigen. Only a small component, around 20% of the antibodies, was directed at major histocompatibility complex (MHC) antigens. In contrast, the DA anti-LEW kidney serum, which was much weaker, was directed entirely at autoantigens, and was more complex in that at least two autoantigens were involved. None of the DA and LEW kidney autoantibodies reacted with lymphocytes. The potential of this assay system for the study of tissue-specific antibodies, especially autoantibodies in man, is discussed.