Background: Chronic allograft nephropathy (CAN) is the most common cause of long-term renal-allograft dysfunction and the second most common cause of transplant loss. There are concerns that prolonged patient exposure to calcineurin inhibitors (CNIs) exacerbates or promotes the process of CAN.
Methods: In our unit, we carried out an observational study over the period 2000 to 2003 using low-dose mycophenolate mofetil (MMF) to facilitate a phased reduction in the dose of CNI in a group of patients with CAN. Low doses of MMF were chosen to minimize adverse effects and to reduce levels of CNIs without the attendant risks of under-immunosuppression.
Results: A step-wise reduction in mean reciprocalised creatinine was evident over the run-in period (mean 1/creatinine before MMF=0.005739-0.000083*month; R=0.77) with a step-wise monthly improvement postintroduction of MMF and dose reduction of CNI (mean 1/creatinine after MMF=0.004609+0.000049*month; R=0.74) (P<0.0001). The mean Cockroft-Gault estimated creatinine clearances were 47.1+/-24.2, 37.2+/-16.3, and 41.6+/-21.1 mL/min at time [t]=-12, t=0 and t=+12 months, respectively. Low-dose MMF therapy was well tolerated (only 7/89 patients stopped MMF because of side-effects in the first 12 months), and acute rejection was noted in only one patient. At latest follow-up, only 17 transplant losses had occurred, of which 6 patients had died with a functioning graft.
Conclusions: Low-dose MMF was well tolerated and resulted in prolonged graft survival.