Ten Years of Treatment With Tacrolimus Is Related to an Excellent Renal Function, Allowing Monotherapy in a Large Proportion of Cases: Unicentric Results of the Tacrolimus Versus Cyclosporine A European Multicentric Study in Kidney Transplant Patients

Abstract

Tacrolimus (Tac) is the most frequently used base inmunosuppressant for transplantation in Spain and the United States. However, long-term data on its use in renal transplant patients are lacking. The aim of this study was to analyze the 10-year outcome of patients from our institution treated with Tac or cyclosporine (CsA) who were included in the European Multicenter Study of kidney transplantation (1993 to 1994). This trial compared the efficacy and safety of steroids + Tac + azathioprine versus steroids + CsA + azathioprine at 1 year, showing a significantly lower acute rejection rate in Tac patients, with no differences in graft or patient survival. In our long-term analysis, we included patients with a functioning graft after the first year: 15 patients on Tac and 11 on CsA. In the “intent-to-treat” (ITT) analysis, patient survival was 14/15 (93%) versus 9/11 (82%) and death noncensored graft survival was 10/15 (67%) versus 8/11 (73%) in Tac and CsA, respectively. Analyzing patients “into treatment” (TT), death/noncensored graft survival was 11/16 (69%) versus 6/9 (67%), respectively. Serum creatinine tended to be lower in Tac group (ITT 1.26 ± 0.42 vs 1.63 ± 1.16 mg/dL, P = NS; TT 1.23 ± 0.4 vs 1.86 ± 1.28 mg/dL, P = NS). However, in the TT analysis, Tac patients exhibited a significantly better creatinine clearance (89.3 ± 40 vs 46.8 ± 21 mL/min, P = .037) and lower systolic blood pressure (125 ± 5 vs 140 ± 12 mm Hg, P = .007) at 10 years. No other significant differences were observed in blood pressure, lipid profile, or glucose metabolism. Outstandingly, Tac monotherapy was the most frequently used regimen after 10 years: ITT 6/9 (67%) versus 1/8 (12.5%), P = .05, TT 7/10 (70%) versus 0/6 (0%), P = .011. Patients under Tac monotherapy exhibited an excellent graft function (serum creatinine 1.08 ± 0.14 mg/dL) and negative proteinuria, with Tac trough levels of 7.9 ± 1.3 ng/mL. In summary, our results suggest that Tac-based immunosuppression provides an excellent kidney function 10 years after transplantation and allows monotherapy in a high percentage of kidney transplant patients.