The Role of the Immunosuppressant Mycophenolate Mofetil in Pediatric Renal Transplant Recipients

The immunosuppressive agent mycophenolate mofetil (MMF) is being used since 1996 also in pediatric renal transplant recipients. There is no doubt that MMF is of clinical benefit in the initial posttransplant period in pediatric renal transplant recipients. Two multicenter trials have provided evidence that MMF at the daily dose of 1200 mg/m2 body surface area given in two divided doses in conjunction with cyclosporin A (CsA) and prednisolone is superior to azathioprine in the pediatric renal transplant population. The tolerability of MMF in children is in general acceptable; the most frequent side effects necessitating dosage reduction are diarrhea and/or nausea and leukopenia. Some arguments for giving MMF as a long-term maintenance immunosuppressive agent are based on what it does not do: it does not cause lipid or carbohydrate metabolism abnormalities or organ toxicity (e.g., hepatotoxicity, nephrotoxicity, or neurotoxicity), it is not mutagenic, and it does not inhibit longitudinal growth. MMF is sufficiently powerful to allow a decrease of potentially nephrotoxic CsA in the stable phase posttransplant in children with chronic transplant nephropathy without the burden of acute rejection, and there is growing evidence for a steroid sparing potential of MMF in this patient population. The therapeutic potential of MMF may be optimized in the future by therapeutic drug monitoring. The estimation of mycophenolic acid (MPA) exposure in children is probably best achieved by use of an abbreviated area under the concentration curve. A large multicenter prospective randomized FDCC-study involving both adult and pediatric renal transplant recipients is currently investigating whether a concentration-controlled (CC) dosing of MMF is superior to a fixed dose (FD) regimen regarding efficacy and tolerability.