Early sirolimus therapy in renal transplant recipients at high risk: is it justified?

We studied early sirolimus (SRL) therapy in renal transplant recipients at high risk after administration of antithymocyte globulin or interleukin-2 receptor blockade induction.

In 45 patients, SRL therapy was started within 1 month after transplantation. The primary indications for conversion of treatment from calcineurin inhibitors (CNIs)-mycophenolate mofetil (MMF)-steroid to SRL-MMF-steroid were biopsy-proved rejection (after treatment), CNI toxicity, CNI elimination, and acute tubular necrosis. Pediatric, geriatric, and other patients with medical comorbidities were not excluded.

Post-SRL rejection episodes were reported in 22.2% of recipients including 15.6% who were resistant to steroid therapy. Mean (SD) follow-up after SRL therapy was 59.9 (8.1) months. Proteinuria greater than 2 g/d (P = .001), leukopenia (P < .001), hyperlipidemia (P < .001), and transaminases values (P = .02) increased significantly after SRL therapy. Graft survival was 88.8%, and patient survival was 93.3%. There was significant improvement in serum creatinine concentration and estimated creatinine clearance by the end of the study (P < .001). A high incidence of adverse effects and infections was noted post-SRL therapy, and the drug was discontinued in 31% of patients because of multiple adverse effects. At multivariate analysis, age, hypertension, nutritional status, bone marrow suppression, hyperlipidemia, and graft dysfunction were identified as risk factors for worse graft and patient outcome.

Early treatment with combined SRL-MMF-steroid may be effective as a CNI-free immunosuppression regimen in patients at high risk; however, there is a high rate of adverse effects during long-term follow-up.