Is sirolimus a safe alternative to reduce or eliminate calcineurin inhibitors in chronic allograft nephropathy in kidney transplantation?

We evaluate whether cyclosporine (CsA) or tacrolimus (FK) could be reduced or eliminated after sirolimus was added in chronic allograft nephropathy (CAN). By reducing doses of CsA or FK, we expected that renal function would improve. Twenty-one patients with CAN had sirolimus added as an immunosuppressive agent. We evaluated the creatinine (Cr) level 3 months after addition. The doses of CsA and FK were decreased gradually and then eliminated over a course of 4 to 6 weeks. If the Cr level rose rapidly or other prominent signs of rejection occurred; low-dose CsA or FK would be added per protocol. We evaluated the duration of engraftment before sirolimus and the Cr level when it was added. Renal function improved in 13 of 21 cases. The improvement in Cr ranged from 12.5% maximally to 1.84% minimally. Seven of 13 cases still required low-dose CsA. The average duration of engraftment before sirolimus was 13.66 ± 10.80 months. The average Cr level before sirolimus was 1.65 ± 0.56 mg/dL. In the other eight cases, the Cr level kept rising from 5.1% to 20.4%. The average duration of engraftment was 88.38 ± 42.21 months. The average Cr level before sirolimus was 2.85 ± 0.54 mg/dL. Hyperuricemia was noted in 31.3% and hyperlipidemia in 68.8%. Sirolimus is a safe alternative to reduce or eliminate CsA or FK in CAN. In cases with a long duration of engraftment and high Cr level, sirolimus might have some effect as a substitute for CNI and thus prevent further nephrotoxicity.