Efficacy of Living Donor Liver Transplantation for Patients With Methylmalonic Acidemia

Application of liver transplantation to methylmalonic acidemia (MMAemia) is controversial because MMAemia is caused by a systemic defect of methylmalonyl-CoA mutase. The clinical courses of seven pediatric patients with MMAemia undergoing living donor liver transplantation (LDLT) were reviewed. Serum and urinary methylmalonic acid (MMA) levels were found to be significantly decreased after LDLT, whereas serum and urinary MMA levels did not return to normal in any patient. One patient died of sepsis 44 days after LDLT. The other six patients are currently doing well. All patients had preoperative history of acute metabolic decompensation and/or metabolic stroke. However, no episode of acute metabolic decompensation or metabolic stroke was observed postoperatively in any surviving patients. In the preoperative period, all patients showed lethargy and cognitive deficit, both of which were eradicated after LDLT in all surviving patients. Preoperatively, all patients were subjected to dietary protein intake restriction and tube feeding, and were administered several metabolism-correcting medications. The metabolism-correcting medications being administered remained mostly unchanged after LDLT, whereas protein restriction was liberalized and tube feeding became unnecessary in all surviving patients. In addition, physical and neurodevelopmental growth delay remained in all surviving patients during the observation period, which ranged from 4 to 21 months with a median of 10.5 months.