Long Term Follow‐Up After Transplantation in Propionic Acidemia: A Retrospective French Pediatric and Adult Cohort Study

ABSTRACT Propionic acidemia (PA) is a rare inherited metabolic disorder associated with recurrent metabolic decompensations and chronic multisystemic complications. Liver transplantation (LT) may improve metabolic stability, but its long‐term impact on organ involvement remains debated. We retrospectively studied 20 patients with PA transplanted between 1993 and 2024 in three French reference centers. Clinical, biochemical, and organ‐specific data were collected before and after transplantation. Eighteen isolated LT and two combined liver–kidney transplantations were performed. Median age at transplantation was 13.6 years; median follow‐up was 4.5 years. Indications included frequent metabolic decompensation (70%) and cardiomyopathy (35%). Four patients died perioperatively, three from cardiac causes; crude survival was 75%. Transplantation markedly improved metabolic stability and allowed significant dietary liberalization, with reduced need for enteral feeding. Cardiac involvement, present in 15 patients pre‐transplant, showed variable evolution: 10 improved initially, but three deteriorated later, and one required heart transplantation. New neurological manifestations occurred in eight patients, with acute episodes including CNI‐related encephalopathy. Psychiatric disorders progressed from 40% to 59% of patients, requiring treatment in seven. Renal impairment worsened post‐LT to 70%, with mean measured glomerular filtration rate declining from 72 to 60 mL/min/1.73 m 2 . LT improves metabolic and nutritional outcomes but does not consistently prevent chronic organ complications. In conclusion, early LT, before the onset of cardiac, neurologic, and psychiatric manifestations, should be considered on a case‐by‐case basis, as we could not demonstrate correlation between age at transplantation and organ involvement.