IMMUNOSUPPRESSIVE DRUG THERAPY IN CANINE RENAL AND SKIN HOMOGRAFTS

Abstract

Seven drugs or combinations of drugs have been used to suppress the immune response to renal homografts in 79 bilaterally nephrectomized dogs: Actinomycin C alone; Imuran in combination with 6-methylamino-purine; Imuran in combination with 4-hydroxypyrazolopyramidine; Imuran in combination with Actinomycin C; Imuran in combination with Methotrexate; Imuran in combination with Azaserine; and Imuran in combination with 6-diazo-5-oxo-L-norleucine. The combination of Imuran and Azaserine has proven the most effective for both survival and function of the transplant. The specificity of drug tolerance in long term survivors has been tested by subsequent skin homografts from the kidney graft donors and from indifferent third party donors. All skin grafts were rejected. Cross reaction with the kidney transplant is evaluated and discussed. Incipient rejection of the renal homo-grafts was treated with Acinomycin C and cortisone and was effective in 50% of the cases. Two renal homografts from unrelated donors were transplanted into the same recipient. Results indicate that the origin of the kidney rather than the aggressiveness of the host''s immune response is responsible to some degree for these prolonged survivals. Specific pre-treatment of the host with antigen and drug therapy was tested; no prolonged survivors were obtained by these methods.