Mycophenolate mofetil in liver transplant patients with calcineurin-inhibitor-induced renal impairment

Background: Calcineurin inhibitors (CNIs) provide effective immunosuppression after orthotopic liver transplantation (OLTx), but the associated nephrotoxicity can cause substantial morbidity and mortality among transplant patients. In this study, we retrospectively investigated the efficacy and safety of mycophenolate mofetil (MMF) in OLTx patients with CNI-induced renal impairment. Patients & Methods: A chart review was undertaken of all liver transplant recipients followed at the Vancouver General Hospital. Twenty-one (12 male) patients were converted to either MMF monotherapy (n = 18) or MMF with corticosteroids (n = 3) for CNI-induced renal dysfunction. Six were excluded because of other factors contributing to renal dysfunction. Mean time from OLTx to conversion was 11.3 years and mean age was 60. Non-parametric Wilcoxon's signed rank testing was used to determine whether there was a difference between the serum creatinine (SCr) before conversion, and 3 or 6 months after conversion. Results: Median follow-up was 294 days, ranging from 35 to1103 days. The median SCr was significantly reduced from 144 mu mol/L before conversion to 129 mu mol/L and 139 mu mol/L at 3 and 6 months follow-up (p = 0.001 and 0.008, respectively). MMF was well tolerated. Only one patient (6.7%) had elevated liver enzymes and required addition of sirolimus while two (13.4%) experienced gastrointestinal intolerance. Conclusions: MMF appears to be safe for stable OLTx recipients with CNI-induced nephrotoxicity. Serious side effects were uncommon as only one patient required discontinuation of the medication. However, longer follow-up and larger study populations are needed in the future to better determine its efficacy and safety.