Cyclosporine versus azathioprine: a 5-year followup of 200 consecutive cadaver renal transplant recipients.

When cyclosporine was introduced as an immunosuppressive agent, there was concern that cyclosporine could be detrimental to long-term renal allograft function and survival. In response to this concern, we report a 5-year followup of 200 consecutive renal transplant recipients among whom initial immunosuppression and risk factors were similar except for the substitution of cyclosporine for azathioprine in the second 100 recipients. The azathioprine and cyclosporine groups had similar 1-year (89% versus 91%) and 5-year (74% versus 80%) patient survival rates. Cyclosporine treated patients had superior 1-year (83% versus 58%) and 5-year (61% versus 29%) graft survival rates. At the 5-year interval, cyclosporine treated grafts had an elevated, yet stable, mean serum creatinine level compared to azathioprine treated grafts. Despite ongoing mild renal dysfunction in cyclosporine treated grafts, cyclosporine does not induce an inexorable decrease in graft function and continues to provide long-term graft survival superior to azathioprine.