Conversion from calcineurin inhibitor to sirolimus for renal function deterioration in kidney allograft recipients

BACKGROUND: Calcineurin inhibitors play an important role in chronic allograft dysfunction. Sirolimus is an interesting alternative in renal transplant patients because it is less nephrotoxic than calcineurin inhibitors. METHODS: A chart review of the clinical outcome of kidney transplant patients converted to sirolimus with progressive allograft dysfunction is reported herein. Fifteen patients (average age: 32.3 years, 44 months mean time of conversion) were included. Indication for conversion was a >20% increase in serum creatinine over the last 6 months or progression to the range of 2-4.5 mg/dL. Patients underwent abrupt cessation of cyclosporine and sirolimus addition at 2-5 mg/day. RESULTS: Concomitant immunosuppression remained unchanged during conversion. Targeted sirolimus level was 8-12 ng/mL. Serum creatinine dropped from pre-conversion level of 2.75 +/- 0.83 to 2.14 +/- 0.67 and 1.97 +/- 0.66 mg/dL at 3 and 6 months (p <0.05). There was a significant decrease in blood urea nitrogen, hemoglobin and serum calcium at 3 months post-conversion as well as serum calcium and potassium at 6 months post-conversion (p <0.05). There were no rejection episodes. Patient and graft survival was 100% with three infectious complications. CONCLUSIONS: Monitored sirolimus conversion with sharp withdrawal of calcineurin inhibitor is an alternative for patients with deteriorating renal function and chronic allograft nephropathy.