Mycophenolate Mofetil Dose Reduction in Renal Transplant Recipients: A 5-Year Follow-up Study

Abstract

Mycophenolate mofetil (MMF), an immunosuppressant that is widely used in renal transplantation, is associated with several dose-dependent hematologic and gastrointestinal side effects that may require dose reduction or even discontinuation. The aim of this study was to compare renal allograft function and acute rejection episodes among kidney allograft recipients who were on 2 regimens of MMF for at least 5 years. This prospective cohort of 55 kidney allograft recipients was followed for deterioration of allograft function, evidence of acute rejection, and allograft survival. Twenty-two patients (40%) underwent MMF dose reduction to 1.35 to 0.23 g/d due to perceived side effects or economic reasons (group 1). The mean time for this change was 4.2 +/- 2.1 months after kidney transplantation. The remaining patients (group 2, n = 33) were continued on MMF (2 g/d). All patients were followed for at least 5 years after transplantation. Renal function tests (blood urea and serum creatinine) were measured monthly for 2 years and then every 2 months. Statistical analysis was performed using SPSS 11.0 (Student t test). P <or= .05 was considered significant. The 2 groups were comparable regarding age, gender, and immunosuppressive medications. The renal function tests were comparable at the end of the study. Mean blood urea values were 44.8 +/- 5.8 and 46.8 +/- 6.8 mg/dL in groups 1 and 2 (P > .05); mean serum creatinine values were 1.32 +/- 0.14 and 1.38 +/- 0.21 mg/dL, respectively (P > .05). There were 2 graft losses and 1 patient loss in group 2. There were also 2 graft losses among group 1 patients. Our study showed that MMF dose reduction was not associated with an increased risk of acute renal allograft rejection or impaired allograft function at 5 years.