Abstract: SA-PO384
Dialysis for an Adult with Maple Syrup Urine Disease
Session Information
- Genetic and Diagnostic Trainee Case Reports
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 701 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Ray, Matthew, University of Colorado Denver, Aurora, Colorado, United States
- Jani, Alkesh, University of Denver Colorado, Aurora, Colorado, United States
Introduction
Maple syrup urine disease (MSUD) is a rare genetic defect in branched chain amino acid (BCAA) metabolism which, if untreated, leads to accumulation of isoleucine accompanied by significant neurologic decompensation and even death. MSUD predominantly affects children and there is little data regarding the utility of renal replacement therapy (RRT) to correct metabolic derangements in adults with MSUD.
Case Description
We present the case of a 39-year-old man who was admitted to our facility with acute encephalopathy as a consequence of decompensated MSUD secondary to acute gastrointestinal bleed likely from prolonged high-dose NSAID use. He was transferred with cerebral edema attributed to an elevated leucine level of 2900 umol/L. The patient’s baseline levels of leucine, at which he had minimal symptoms, was ~ 1000umol/L. Given the encephalopathy and cerebral edema, he was initially started on CVVHD with monitoring of mental status and leucine levels. Despite RRT, the patient remained symptomatic, raising the possibility his leucine levels were still elevated. He was therefore switched to intermittent hemodialysis for four hours to facilitate rapid removal of leucine, followed by resumption of CVVHD. CRRT was continued for a further 12 hours, with improvement in his leucine levels to <800 and in mental status. The patient made a full recovery and was discharged home 4 days later.
Discussion
Maple syrup urine disease is an inborn error of metabolism of BCAA, characterized by mutations in genes that result in a deficiency of the branched-chain alpha-keto acid dehydrogenase complex that is required to metabolize BCAAs. The disorder gets its name because the urine of affected infants has sweet odor. A specialized diet can prevent accumulation of BCAAs in these patients. However, any hypercatabolic state, including stressors such as infection, injury, and a failure to eat (as occurred in our patient due to his GI bleed), can lead to a metabolic derangement with a rapid increase in amino acid levels and accompanied clinical deterioration. Much of the experience in treating such patients nests in pediatric academic centers and literature, and physicians caring for adult patients have little experience with these complicated cases. Our case therefore illustrates a successful approach to managing metabolic crisis in the setting of an acute metabolic decompensation in an adult patient with MSUD.