Clinical analyses of living donor liver transplantation for methylmalonic acidemia in children

Objective To explore the clinical efficacy of living donor liver transplantation (LDLT) for children with methylmalonic acidemia (MMA). Methods From November 2016 to April 2019, clinical data, perioperative outcomes, complications and mid-term follow-up data of 30 MMA children receiving LDLT were retrospectively analyzed. Results All recipients were vitamin B12-ineffective. There were 20 boys (66.7%) and 10 girls (33.3%) with a median age of 33(6-144) months at transplantation. And the median values of height and body weight were 87(61-137) cm and 11.0(7.0-29.0) kg respectively. The median graft-to-recipient weight ratio was 2.1% (1.0%-3.2%). All of them belonged to Child-Pugh class A. All donors were biological parents as a heterozygous carrier of pathogenic gene. Surgical complications occurred in 4 cases (13.3%), including hepatic artery thrombosis (n=1), biliary complications (n=1), hepatic vein complications (n=1) and intestinal perforation (n=1). The median follow-up period was 18(6-34) months. The posttransplant survival rates of patients and grafts were 100% and 96.3% respectively. No severe intolerable decompensated metabolic acidosis occurred after transplantation. Compared with pre-transplantation, the levels of propionylcarnitine and the ratios of propionylcarnitine to acetylcarnitine in blood and levels of methylmalonic acid and 3-hydroxypropionic acid in urine decreased markedly at 3 months post-transplantation. Conclusions LDLT using grafts from parental donors as a heterozygous carrier for MMA can significantly reduce the risks of decompensated metabolic acidosis and greatly improve the quality-of-life of children. Key words: Living donor; liver transplantation; Children; Methylmalonic acidemia