Mycophenolate mofetil vs azathioprine in a large population of elderly renal transplant patients

Background. Mycophenolate mofetil (MMF) has been shown to decrease acute rejection episodes after kidney transplantation, and has been associated with better graft and patient survival vs azathioprine (AZA). Previous studies reported a higher risk of death due to infection in elderly recipients treated with MMF-based immunosuppression. Methods. We analysed 5069 elderly (> 65 years of age) primary renal allograft recipients treated with either MMF or AZA reported to the Scientific Registry of Transplant Recipients between 1988 and 2000, and compared rates of acute rejection, late acute rejection, graft survival, death-censored graft survival, patient survival and death with a functioning graft. Results. In Cox proportional hazard models, MMF was associated with lower rates of late acute rejection with 12 (RR = 0.72, P = 0.11) and 24 months (RR = 0.50, P = 0.028) of continuous therapy. In univariate analysis (Kaplan-Meier), MMF was associated with improved patient (P = 0.0003) and graft (P < 0.0001) survival vs AZA, and trends toward improved patient and graft survival in multivariate analyses. Conclusions. These findings demonstrate the efficacy of MMF-based immunosuppression in elderly transplant recipients and do not suggest an increased risk of death compared to treatment with AZA.