Conversion to Sirolimus Allows Preservation of Renal Function in Kidney and Kidney-Pancreas Allograft Recipients

The major causes of graft failure are chronic allograft nephropathy (CAN) and patient mortality. Sirolimus (SRL) is a powerful immunosuppressant with a less nephrotoxic profile as well as a lower incidence of cancer. The aim of this study was to evaluate the impact of conversion to SRL from calcineurin inhibitor (CNI)-based therapy in kidney (KT) and kidney-pancreas (SPK) allograft recipients. We analyzed renal function, allograft and patient survival, and SRL-associated adverse effects in 93 adult patients (86 KT and 7 SPK), who were converted to SRL between January 2001 and November 2008. The main reason for conversion was CAN (76; 9%) and 52 (7%) were receiving tacrolimus. Conversion occurred at a median 26.2 months. There was a significant improvement in creatinine clearance (CCr) at 6 months after conversion (CCr(baseline) 51.4 vs CCr(6m) 60.4 mL/min; P <.0001), without changes at 1.2 and 24 months. However, proteinuria increased significantly at 6 months compared with the baseline: 150 mg/24 hours (0-453) versus 0 mg/24 hours (range, 0-309), respectively (P <.0001), but did not progress at 1.2 or 24 months. At the same time we observed more extensive use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers: 60/5%; 65/3% and 70/2% at 6, 12, and 24 months. There were no changes in blood pressure control. Cholesterol significantly increased at 6 months (218.2 +/- 37 vs. 186.6 +/- 44 mg/dL; P<.0001.). Graft and patient survivals at 4 years were 88% and 95%, respectively. Our experience suggested that conversion to SRL constituted a safe alternative with excellent results in patient and graft survival.