Mycophenolate mofetil dose reductions and discontinuations after gastrointestinal complications are associated with renal transplant graft failure

Background. Mycophenolate mofetil (MMF) use in renal transplantation has steadily increased since 1995 because of its ability to lower the risks of rejection and chronic allograft nephropathy. However, significant gastrointestinal (GI) complications may lead to MMF dose reductions and discontinuations. Little is known of the association between MMF dose reductions and discontinuations following GI complications and graft survival. Methods. Using the United States Renal Data System, we identified 3,675 adult recipients (age 18) with a diagnosed GI complication who were prescribed MMF at the time of first GI diagnosis and had Medicare as their primary insurer. MMF doses were ascertained from Medicare payment records. We estimated risk of graft loss associated with MMF dose adjustments after GI diagnosis: dosage unchanged (reference), reduced < 50%, reduced >= 50%, and MMF discontinued. Patients were followed until graft loss, death, last recorded immunosuppression prescription, or 3 years posttransplant. Results. Compared to those with no MMF dose reductions or discontinuations, the risk of graft failure increased with MMF doses reduction >= 50% (HR=2.36, 95% CI 1.23-4.54) and those with MMF discontinuation (2.72, CI 1.604.64). Conclusion. Renal transplant recipients who underwent MMF dose reduction or withdrawal following GI diagnosis are associated with increased risk of graft failure.