Organic acids and branched-chain amino acids in body fluids before and after multiple exchange transfusions in maple syrup urine disease

J Inherit Metab Dis. 1983;6(4):183-9. doi: 10.1007/BF02310879.


We successfully treated a critically ill infant with the classical type of maple syrup urine disease by multiple exchange transfusions via a peripheral artery and vein and with positive calorie supplementation in the early stage of therapy. Clinical improvement was definite after the plasma leucine level fell below 1 mmol/l. There was a close linear correlation between plasma concentrations of branched-chain amino acids and their corresponding branched-chain alpha-keto acids and branched-chain alpha-hydroxy acids. alpha-Hydroxy acids were more easily excreted in the urine than alpha-keto acids and amino acids. Our studies on urinary organic acids supported the existence of minor metabolic pathways of branched-chain alpha-keto acids, although they were not thought to be important in eliminating accumulated alpha-keto acids. Urinary excretion of succinic acid and alpha-ketoglutaric acid, which are components of the citric acid cycle, increased transiently during the patient's convalescence. The cerebrospinal fluid/plasma ratios for branched-chain amino acids, alpha-keto acids, and alpha-hydroxy acids were very high before the transfusions and decreased after improvement. The cerebrospinal fluid/plasma ratios for 5-carbon acids, alpha-ketoisovaleric acid and alpha-hydroxyisovaleric acid were much higher than for other branched-chain acids not only in the patient but also in normal controls. Cerebrospinal fluid levels of alpha-ketoisocaproic acid and alpha-hydroxyisovaleric acid were as high as 1 mmol/l in our patient.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Branched-Chain / metabolism*
  • Body Fluids / metabolism*
  • Carboxylic Acids / metabolism*
  • Exchange Transfusion, Whole Blood*
  • Female
  • Humans
  • Hydroxy Acids / metabolism
  • Infant, Newborn
  • Keto Acids / metabolism
  • Ketoglutaric Acids / urine
  • Maple Syrup Urine Disease / therapy*
  • Succinates / urine
  • Succinic Acid


  • Amino Acids, Branched-Chain
  • Carboxylic Acids
  • Hydroxy Acids
  • Keto Acids
  • Ketoglutaric Acids
  • Succinates
  • Succinic Acid