Background Mycophenolate mofetil (MMF) has been previously shown to pr
event functional deterioration in an experimental model of chronic ren
al allograft rejection. Methods. In this retrospective case-control st
udy, patients with chronic rejection who were receiving cyclosporine o
r tacrolimus and who had MMF added to their immunosuppressive regimen
were compared with patients with chronic rejection who were not receiv
ing MMF. Patients were matched for serum creatinine levels and transpl
ant duration at the time MMF was begun. Results. In the MMF group, the
average dose of MMF was 1482 mg/day with an average duration of 19.3
months. Over 36 months, including 12 months before MMF and up to 24 mo
nths on MMF, there was no difference in serum creatinine levels betwee
n the two groups. Cyclosporine levels and dose were no different. Conc
lusions. In this small, retrospective, preliminary study, adding MMF t
o maintenance immunosuppression provided no clear benefit to renal all
ograft recipients with established chronic rejection. Larger prospecti
ve randomized studies are needed.