Acute liver failure (ALF) is defined as severe and sudden liver dysfunction leading to coagulopathy and encephalopathy in a previously healthy person without preexisting liver disease. Almost half of adult cases of ALF are due to acetaminophen toxicity, with 21% labeled indeterminate or other. We present a patient with a second episode of ALF, both episodes being initiated by catabolic stress. Elevated aminotransferases, jaundice, an elevated international normalized ratio, and confusion were typical of idiopathic ALF, and a low serum ceruloplasmin level initially led to a misdiagnosis of acute Wilson disease. Citrullinemia type I, a urea cycle defect caused by a deficiency of argininosuccinate synthetase, was diagnosed on the basis of plasma amino acids and was confirmed by molecular testing. Urea cycle defects are not generally considered causes of ALF in adults and are described rarely in children beyond the neonatal period. Our case illustrates the importance of screening patients with idiopathic ALF for a metabolic disorder. A prompt diagnosis and timely treatment enabled her to recover fully without the need for liver transplantation.
(c) 2010 AASLD.