Mycophenolate mofetil (MMF) decreases the risk of acute rejection and is associated with improved graft survival in renal transplant recipients. However, MMF-related side effects often necessitate dose reduction which may expose transplant recipients to a higher risk of acute rejection and graft loss. This study's aim was to examine the reasons for MMF dose reduction during the first year after kidney transplantation and its impact on acute rejection, overall and death-censored graft loss. Methods: Retrospective electronic file based analysis of all patients who underwent a single kidney transplantation in our center between 1996 and 2007 and were treated with MMF as part of their initial maintenance immunosuppressive protocol (n=749).

Inclusion Criteria:

• All patients who received a single renal transplant at the University Hospitals of Leuven between April 1996 (when MMF was introduced in the Leuven renal transplant program) and February 2007 and were treated with MMF (Cellcept®, Roche) as part of their initial maintenance immunosuppressive regimen were included in this retrospective analysis.

Exclusion Criteria:

• If a patient underwent more than one kidney transplantation in the abovementioned 11-year period, only the last was considered.

All patients who received a single renal transplant at the University Hospitals of Leuven between April 1996 (when MMF was introduced in the Leuven renal transplant program) and February 2007 and were treated with MMF (Cellcept®, Roche) as part of their initial maintenance immunosuppressive regimen were included in this retrospective analysis. If a patient underwent more than one kidney transplantation in the abovementioned 11-year period, only the last was considered. No other exclusion criteria were applied.