Comparison of sirolimus with low-dose tacrolimus versus sirolimus-based calcineurin inhibitor-free regimen in live donor renal transplantation

Between May 2001 and January 2003, 132 live donor renal allotransplant recipients were included in a prospective, randomized controlled trial where they were divided into two groups. All patients received steroids and basiliximab induction therapy. For maintenance immunosuppression, tacrolimus and sirolimus were used in group A. In group B, mycophenolate mofetil (MMF) and sirolimus were utilized. Patients were followed up for a minimum of 24 months. One-year patient and graft survival rates were not significantly different between group A (96.9%, 92.3%) and group B (100%, 98.4%), respectively. However, the incidence of biopsy-proven acute rejection was less in group B but the difference was not statistically significant (13.5% vs. 18.5% in group A). Statistically significant better renal function was encountered among group B patients at two years post-transplantation as measured by serum creatinine (1.25 vs. 1.43 mg/dl; P = 0.017) and calculated glomerular filtration rate (GFR) (94.9 vs. 79.6 ml/min; P = 0.005). One year protocol biopsies showed insignificant differences relative to chronic allograft damage index (CADI) between either group (Group A: 2.41 vs. Group B: 2.69; P = 0.436). Conclusion: Similar outcome was noted among patients in whom calcineurin inhibitors were not included in their immunosuppressive regimen. The long term impact of this observation on graft survival and function needs longer follow up.