Reuters Health Information (2011-09-06): Consider liver transplant for maple syrup urine disease: study
Consider liver transplant for maple syrup urine disease: study
Last Updated: 2011-09-06 18:18:01 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Liver transplantation may be a reasonable long-term option for children with the most common variant of maple syrup urine disease (MSUD), according to a new report from the University of Pittsburgh.
"The risks and benefits of transplant need to be carefully weighed against the risks and benefits of medical management," Dr. George V. Mazariegos, Director of Pediatric Transplantation at Children's Hospital of Pittsburgh, told Reuters Health by email.
"Liver transplantation should be considered for all patients with the classic variant" of this inborn error of metabolism, Dr. Mazariegos said.
But that needs to be done "in centers with considerable experience in the management of both metabolic liver disease and transplantation," he said.
Dr. Mazariegos and his team have found that liver transplant can halt the brain damage associated with MSUD -- but not reverse it.
In an August 10 online article in the Journal of Pediatrics, the researchers explain that MSUD disrupts the body's metabolism of branched-chain amino acids and can lead to mental retardation and even death. Patients are prone to cerebral edema, brain herniation, cardiac arrest and cognitive impairment.
Treatment is usually a diet low in branched-chain amino acids, but the diet restrictions can have unpredictable neurological affects, Dr. Mazariegos said. In earlier research, he showed that liver transplantation can control the metabolism of these amino acids.
The new study included 54 children with MSUD who received new livers, including 37 from the researchers' center and 17 from the national registry of the United Network for Organ Sharing (UNOS).
Overall, at 4.5 years, patient survival was 98% and graft survival was 96%. In the 37 patients treated in Pittsburgh, patient and graft survival were both 100%.
Thirty-three children in the Pittsburgh cohort took IQ tests and 31 took adaptive behavior tests before their transplant surgery. Most scored below average. Eleven scored 70 or below on the IQ test, signifying mental retardation, while only eight scored average or higher on the adaptive skills tests.
One year after the transplantation, IQ and adaptive tests in 14 patients showed a tendency toward slightly higher scores, but it was statistically insignificant.
Dr. Mazariegos and his colleagues have done some of the nation's first domino transplants of livers from MSUD patients to recipients with other conditions. Six of the children they treated in this new study donated their livers to other patients without MSUD, and all six of those recipients are alive with normally functioning livers.
J Pediatr 2011.