Rabbit antithymocyte globulin, a "custom-made" pan-
anti-T-cell antibody produced in rabbits, is currently being evaluated in the United States and may, within several years, become approved by the Food and Drug Administration. Because we have used this agent for induction of immunosuppression for 10 years in cardiac recipients and because the results appear to be more favorable than those obtained with other agents (horse
antithymocyte globulin,
antilymphocyte globulin,
OKT3), we have reviewed our experience. For the purpose of analysis, all non-bridge-to-transplant cardiac recipients have been divided into three groups on the basis of immunosuppression protocol: group I (March 1979 to January 1983), 28 patients treated with
rabbit antithymocyte globulin,
steroids, and
azathioprine; group II (January 1983 to March 1985), 29 patients treated with
rabbit antithymocyte globulin,
cyclosporine, and
steroids; and group III (March 1985 to January 1989), 98 patients treated with
rabbit antithymocyte globulin,
cyclosporine,
steroids, and
azathioprine. Actuarial data showed advantage for group III in survival rate (1 year 94%, 2 years 91%, 3 years 88%), freedom from rejection (30% free at 1 year), freedom from
infection (50% free at 1 year), freedom from death from rejection (99% free at 1 year), and freedom from death from
infection (97% freedom at 1 year). Actuarial survival rates and freedom from death from rejection and
infection are comparable for any of our groups with contemporary published data. In the past 3 years, we have had no death from acute rejection or from posttransplant
infection. Time-related rates of
infection by etiologic agents have shown a significant reduction in early bacterial, viral, and nocardial
infections between groups I and III. With
rabbit antithymocyte globulin 200 mg intramuscularly every day for 3 days, our current protocol, T-cells are significantly reduced and local and systemic toxicity is almost unnoticeable. A progressively increasing
cyclosporine dose along with rapid tapering
steroid and maintenance
azathioprine immunosuppressive induction appears to be the
therapy of choice in
cardiac transplantation.