Serum Trough Concentration and Effects of Mycophenolate Mofetil Based on Pathologic Findings in Infants After Liver Transplantation

Abstract

ObjectivesMycophenolate mofetil (MMF) is mainly used in conjunction with calcineurin inhibitors as an additional immunosuppressive for renal sparing after liver transplantation. However, few reports about MMF use in infants after living donor liver transplantation (LDLT) are available. The purpose of this study was to examine the efficacy and safety of MMF in infants. MethodsThis study enrolled infants younger than 1 year of age who received LDLT at our institution. Patients received oral MMF twice daily. The initial dose was 40 to 50 mg/kg/d, which was increased to a target mycophenolic acid (MPA) trough level of 2 mg/L. Body weight, height, MMF dose, MPA trough level, acute cellular rejection (ACR) episodes, pathologic findings, and adverse effects were analyzed. Allograft fibrosis was graded using the Meta-analysis of Histological Data in Viral Hepatitis score. ResultsPatients received MMF for refractory ACR (n = 2), fulminant hepatitis (n = 2), and pre-existing antibodies (n = 1). Original diseases were biliary atresia (n = 3) and fulminant hepatitis (n = 2). Mean age at transplant was 8 months (range 3-10 months). The last available mean trough level was 2.7 mg/L. The mean dose was 66 mg/kg/d or 1429 mg/m2/d at the time of the last available through level. The regression line for MMF dose and MPA trough level was y = 1.8 × 10-3x. The correlation coefficient was 0.65. All allografts showed F1 to F2 fibrosis. Two patients discontinued MMF because of infection and bone marrow suppression, respectively. Two patients converted to everolimus. One patient continued on MMF. ConclusionsAfter LDLT, infants require a higher MMF dose than older patients based on trough levels, but allograft fibrosis can progress.