Graft survival following living-donor renal transplantation: A comparison of tacrolimus and cyclosporine microemulsion with mycophenolate mofetil and steroids

Background. Registry databases offer the statistical power to analyze differences in graft survival rates that may not be detected in randomized clinical trials. This study analyses 2-year graft survival using tacrolimus (tac) or cyclosporine (CsA) with mycophenolate mofetil (MMF) and steroids. Methods. Data reported to the United Network for Organ Sharing Renal Transplant Registry for living-donor kidney patients receiving a transplant during 1998 to 1999 were included. The primary end point was graft survival after adjustment for confounding variables. A Cox model multivariate analysis was used to adjust for potential confounding factors. Results. Patients receiving CsA-MMF (n=4,686) and tac-MMF (n=2,393) were included. Unadjusted all-cause 2-year graft survival rate was significantly higher with CsA-MMF than tac-MMF (94.3% vs. 92.2%, P=0.0006). After adjustment for potential confounding factors, risk of graft failure at 2 years was significantly higher in patients receiving tac-MMF versus CsA-MMF for both all-cause graft failure (hazards ratio [HR] 1.28, 95% confidence interval [CI] 1.09-1.49, P=0.002) and death-censored graft failure (HR 1.25,95% Cl 1.05-1.499 P=0.013). Other independent risk factors for graft failure were recipient or donor age greater than 55 years, female sex, pretransplant blood transfusions, one or two haplotype mismatches compared with zero haplotype mismatch, and panel reactive antibody (PRA) greater than 30%. Conclusions. Our findings demonstrate that 2-year renal allograft survival is significantly higher in living-donor recipients receiving CsA compared with tac as initial immunosuppression in combination with MMF.