Living donor liver transplantation for noncirrhotic inheritable metabolic liver diseases: impact of the use of heterozygous donors.

Background: In living donor liver transplantation (LDLT), the liver donor is almost always a blood relative; therefore, the donor is sometimes a heterozygous carrier of inheritable diseases. The use of such carriers as donors has not been validated. The aim of the present study was to evaluate the outcome of LDLT for noncirrhotic inheritable metabolic liver disease (NCIMLD) to clarify the effects of using a heterozygous carrier as a donor.
Methods: Between June 1990 and December 2003, 21 patients with NCIMLD underwent LDLT at our institution. The indications for LDLT included type II citrullinemia (n = 7), ornithine transcarbamylase deficiency (n = 6), propionic acidemia (n = 3), Crigler-Najjar syndrome type I (n = 2), methylmalonic acidemia (n = 2), and familial amyloid polyneuropathy (n = 1). Of these 21 recipients, six underwent auxiliary partial orthotopic liver transplantation.
Results: The cumulative survival rate of the recipients was 85.7% at both 1 and 5 years after operation. All surviving recipients are currently doing well without sequelae of the original diseases, including neurological impairments or physical growth retardation. Twelve of the 21 donors were considered to be heterozygous carriers based on the modes of inheritance of the recipients' diseases and preoperative donor medical examinations. All donors were uneventfully discharged from the hospital and have been doing well since discharge. No mortality or morbidity related to the use of heterozygous donors was observed in donors or recipients.
Conclusions: Our results suggest that the use of heterozygous donors in LDLT for NCIMLD has no negative impact on either donors or recipients, although some issues remain unsolved and should be evaluated in further studies.