メープルシロップ尿症に対する小児肝移植：単一施設での経験

Maple syrup urine disease (MSUD) is an autosomal recessive inborn error of branched-chain amino acid metabolism caused by an inherited deficiency of branched-chain alpha-ketoacid dehydrogenase (BCKDH) activity that degrades isoleucine, leucine, and valine. Liver transplantation (LT) is a therapeutic option to treat the classical severe type of MSUD. This study aimed to assess and compare liver biochemical outcomes and amino BCAAs levels post-LT according to different types of donors.

Retrospective cohort analysis of 10 patient medical records diagnosed as MSUD who underwent LT in King Fahad Specialist Hospital-Dammam between January 2013 and May 2023.

Ten pediatric patients diagnosed with MSUD who had finished 1 year of follow-up after LT were included in the study. The median age of diagnosis among the pediatric patients was 1 month (as it is included in the national neonatal screening). Besides, the median age for LT was 123 months (10 years 3 months) (with a range of 9-173 months). Availability of milk formula, prevention of further neurological insult, and difficulty in controlling the protein intake were the main indications for LT. Post LT, six patients (60%) were immediately initiated on a regular diet, and four patients (40%) waited for 3 months before starting a regular diet. All the patients were on Tacrolimus as immunosuppression, with three patients started on Mycophenolate because of biopsy-proven acute cellular rejection. Our result showed 100% 1-year graft survival and 100% until the time of report, with no donor complications. 70% of the explanted liver had been re-transplanted as a domino liver transplant. No clinical or laboratory difference when comparing living-related to living-unrelated or deceased donor liver transplant. 100% of our patients and families showed satisfaction with the decision of liver transplant.

MSUD post liver transplant showed a 100% graft survival rate, and all patients and families showed satisfaction. In settings with limited deceased donor organs, living-related donor LT (even from heterozygous carriers) is a viable option for MSUD, yielding comparable metabolic control and graft outcomes to other donor types.