title: Effect of treatment with the Molecular Adsorbents Recirculating System on arterial amino acid levels and cerebral amino acid metabolism in patients with hepatic encephalopathy.
abstract: BACKGROUND
  Liver failure is associated with low concentrations of branched-chain amino acids and high concentrations of most other amino acids. In this study the effect of treatment with the Molecular Adsorbents Recirculating System (MARS) on arterial amino acid levels and cerebral amino acid metabolism was examined in patients with severe hepatic encephalopathy.
  
  
  METHODS
  The study included seven patients with hepatic encephalopathy from fulminant hepatic failure (FHF) and five patients with hepatic encephalopathy from acute-on-chronic liver failure (AoCLF). Cerebral blood flow and cerebral arteriovenous differences in amino acids were measured before and after 6 h of treatment with MARS.
  
  
  RESULTS
  During MARS treatment, the total arterial amino acid concentration decreased by 20% from 8.92 +/- 7.79 mmol/L to 7.16 +/- 5.64 mmol/L (P < 0.05). The concentration decreased in all amino acids with the exception of the branched-chain amino acids. Fischer's ratio of branched-chain to aromatic amino acids increased from 0.73 +/- 0.47 to 0.91 +/- 0.54 (P < 0.05). A net cerebral efflux of amino acids in patients with FHF (8.94 +/- 8.34 micromol/100 g/min) as well as AoCLF (7.35 +/- 24.97 micromol/100 g/min) was not affected by the MARS treatment. MARS had no effect on the cerebral metabolic rate of any single amino acid in either group.
  
  
  CONCLUSIONS
  MARS treatment tends to normalize the arterial amino acid concentrations in patients with hepatic encephalopathy. Even though the overall reduction in plasma amino acids and improvement in amino acid dysbalance may well be beneficial, it was not accompanied by any immediate improvement in cerebral amino acid metabolism in patients with FHF or AoCLF.
authors.affiliation: Department of Hepatology, Rigshospitalet, University Hospital, Copenhagen, Denmark. lars.schmidt@dadlnet.dk
authors.forename: L E
authors.initials: LE
authors.lastname: Schmidt
authors.forename: F
authors.initials: F
authors.lastname: Tofteng
authors.forename: G I
authors.initials: GI
authors.lastname: Strauss
authors.forename: F S
authors.initials: FS
authors.lastname: Larsen
mesh_terms: D000328:Adult; D000418:Albumins / Q000378:metabolism; D000596:Amino Acids / Q000097:blood / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D001774:Blood Chemical Analysis; D001812:Blood-Brain Barrier; D003131:Combined Modality Therapy; D016638:Critical Illness / Q000628:therapy; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D006501:Hepatic Encephalopathy / Q000097:blood / Q000175:diagnosis* / Q000628:therapy*; D006801:Humans; D017114:Liver Failure, Acute / Q000097:blood / Q000175:diagnosis* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D012121:Respiration, Artificial; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016060:Sorption Detoxification / Q000379:methods; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D000418:Albumins; D000596:Amino Acids; D015415:Biomarkers