Mammalian Target of Rapamycin Inhibitor Monotherapy: Efficacy in Renal Transplantation

BackgroundCalcineurin inhibitors (CNI) have failed to improve long-term outcomes in renal transplantation. Anti-proliferative and anti-angiogenic effects of mammalian target of rapamycin inhibitors (m-TOR) without nephrotoxicity could improve long-term survival in selected transplant recipients.MethodsWe examined the evolution of 98 low–immunological risk renal transplant recipients on m-TOR monotherapy: 7 patients had induction without CNI and 91 were switched to m-TOR at 12 (p25–p75: 4–36) months after transplant.ResultsMedian follow-up time was 46 (p25–p75: 28.5–72.0) months. Fifteen recipients dropped out of the study (15.3%): 8 patients (8.2%) had to change their immunosuppressive treatment because of complications and 7 (7.1%) lost their grafts as a result of chronic rejection (4 cases) or death with a functioning graft (3 cases). At the end of follow-up, 83 of 98 (84.6%) recipients remained on monotherapy. The rates of recipient and graft survivals were 100% and 98.8% at 2 years and 96.9% and 93.5% at 4 years; the percentages of patients on monotherapy after 2 and 4 years were 95.2% and 85.2%, respectively. Renal function improved significantly and proteinuria decreased but not significantly. Those patients switched to m-TOR significantly received more erythropoietin, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and hypotensive agents than before starting m-TOR, whereas there were no significant changes related to the use of statins, body weight, or percentage of diabetic patients. No case of non-compliance was reported.ConclusionsThis study supports the safety and efficacy of monotherapy with m-TOR in selected renal transplant recipients.