Randomized study comparing cyclosporine with azathioprine one year after renal transplantation-15-year outcome data.

Background: The introduction of cyclosporine (CsA) improved 1-year graft survival and reduced the incidence of acute rejection episodes after renal transplantation compared to azathioprine (Aza). However, CsA has many side effects and reducing exposure of this drug after the first year may benefit long-term patient and graft survival.

Methods: We report 15-year outcome data from a single center, randomized controlled study comparing CsA withdrawal and conversion to Aza with continuation of CsA 1-year posttransplant.

Results: Two hundred sixteen patients who showed a serum creatinine less than 300 mumol/L with no acute rejection episodes in the preceding 6 months were enrolled (CsA 114, Aza 102). There was no difference in patient survival at 15 years: 62.4% in the CsA group and 64.4% in the Aza group (P=0.6). Fifteen-year transplant survival was 41.9% for the CsA group and 48.8% for the Aza group (P=0.8). Fifteen-year graft survival censoring for death with a functioning graft was 58% in the CsA group and 72% in the Aza group (P=0.5). Predictors of patient survival were younger recipient age (P<0.001) and lower systolic blood pressure at randomization (P=0.01). Predictors of graft survival were older recipient age (P<0.001) and better renal function at randomization (P=0.01). Assigned drug showed no effect on graft or patient survival. Patients assigned to CsA showed significantly worse renal function up to 10 years posttransplantation and required more anti-hypertensive treatment throughout the study period.

Conclusion: In a selected group of patients, either Aza or low-dose CsA is safe and effective. Despite lower estimated glomerular filtration rate (eGFR) up to 10 years posttransplantation and increased use of anti-hypertensive agents, low-dose CsA was not associated with a worse patient or graft survival.