Rapamycin: personal algorithms for use based on 250 treated renal allograft recipients

RAPA represents a likely candidate for addition to the maintenance immunosuppressive regimen, for it seems to potentiate markedly the efficacy fo CyA-based therapy. RAPA reduces the incidence of acute rejection episodes; indeed, it may even be useful to disrupt ongoing steroid- and antibody-resistant cellular and humoral acute rejection reactions. Some data in model systems, both in vitro and in vivo, suggest that RAPA may afford prophylaxis against chronic rejection. The enhanced immunosuppression is likely to permit reduction in CyA doses/concentration, thereby mitigating its nephrotoxic effects, and to permit withdrawal of corticosteroids, providing relief from their osteopenic, myopathic, and metabolic effects. As with other potent immunosuppressives, RAPA causes a range of adverse side effects, most importantly myelosuppression and hyperlipidemia. Hypothesis-testing investigations are already underway to elucidate the mechanisms of the adverse effects so as to design strategies to minimize their impact on posttransplant morbidity.