The use of cyclosporine in living-related renal transplantation. Donor-specific hyporesponsiveness and steroid withdrawal.

Fourteen HLA-identical (HLA-ID) and 62 haploidentical (HP-ID) living-related donor (LRD) renal allograft recipients were transplanted using cyclosporine (CsA) and prednisone immunosuppression. No patients were preconditioned with pretransplant blood transfusions (third-party or donor-specific)--and, therefore, none were sensitized to their donor. Patient 93% (13/14) and graft 93% (13/14) survival for the HLA-ID patients is not significantly different (P greater than .1) compared with patient 98% (61/62) and graft 91% (56/62) survival in the HP-ID patients, with a mean follow-up of 16.3 (8-30) and 14.7 (2-35) months, respectively. A significant difference was noted in the incidence of treated rejection episodes (0% vs. 31%, P less than .01) and the mean serum (mg/dl) creatinine (1.37 vs. 1.71, P less than .05) at 18 months between the HLA-ID and the HP-ID and HP-ID recipients, respectively. Ten of 22 HP-ID recipients demonstrated donor-specific mixed lymphocyte culture hyporesponsiveness one year posttransplant that may have been due to the emergence of monocytoid suppressor cells. Nine of these HP-ID and seven HLA-ID recipients were subjected to a protocol of steroid withdrawal. Eleven of these patients are currently on CsA monodrug therapy and two are on alternate-day steroids from 9-18 months after discontinuation of prednisone. These findings suggest that CsA is an effective steroid-sparing agent in LRD renal transplantation that diminishes the frequency of treated rejection episodes and may permit monodrug therapy in selected individuals.