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 (CCrbaseline 51.4 vs CCr6m 60.4 mL/min; P < .0001), without changes at 12 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 12 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.