title: Effects of polymyxin B-immobilized fiber hemoperfusion on amino acid imbalance in septic encephalopathy.
abstract: BACKGROUND
  Septic encephalopathy is a common term denoting the signs of progressing central nervous system dysfunction in septic patients. Metabolic alterations including amino acid imbalance are involved in the pathogenesis of septic encephalopathy. The aim of the present study was to determine whether the ratio of branched-chain amino acids to aromatic amino acids is altered in patients with septic encephalopathy and whether polymyxin B-immobilized fiber (PMX-F) hemoperfusion affects this balance.
  
  
  METHODS
  16 septic patients with encephalopathy, 10 septic patients without encephalopathy, and 20 healthy controls were included in this study. Sepsis was diagnosed according to the ACCP/SCCM Consensus Conference criteria. Plasma endotoxin levels, interleukin-6 (IL-6) levels, and amino acid ratios were measured before and after PMX-F treatment.
  
  
  RESULTS
  Within 12 h of the onset of septic encephalopathy, plasma endotoxin and IL-6 levels were increased significantly in septic patients with encephalopathy in comparison to those in septic patients without encephalopathy (endotoxin, p < 0.05; IL-6, p < 0.01) and those in healthy controls (endotoxin; p < 0.001; IL-6, p < 0.001). The ratio of branched-chain amino acids to aromatic amino acids in septic patients with encephalopathy was decreased in comparison to the ratio in septic patients without encephalopathy (p < 0.05) and that in healthy controls (p < 0.01). PMX-F treatment reduced plasma endotoxin (p < 0.01) and IL-6 levels (p < 0.01) and increased the ratio of branched-chain amino acids to aromatic amino acids (p < 0.01).
  
  
  CONCLUSIONS
  The amino acid imbalance in patients with septic encephalopathy may be a marker for the severity of the septic syndrome, and PMX-F hemoperfusion is effective in ameliorating the increased plasma endotoxin and IL-6 levels and the amino acid imbalance in these patients.
authors.affiliation: Department of Medicine, Shinmatsudo Central General Hospital, Chiba, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kawagoe
authors.forename: Takaharu
authors.initials: T
authors.lastname: Matsuda
authors.forename: Isao
authors.initials: I
authors.lastname: Ebihara
authors.forename: Hikaru
authors.initials: H
authors.lastname: Koide
mesh_terms: D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000097:blood / Q000378:metabolism*; D024322:Amino Acids, Aromatic / Q000097:blood; D000597:Amino Acids, Branched-Chain / Q000097:blood; D001927:Brain Diseases / Q000209:etiology*; D004731:Endotoxins / Q000097:blood; D005260:Female; D006464:Hemoperfusion / Q000379:methods*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011112:Polymyxin B / Q000627:therapeutic use*; D018805:Sepsis / Q000097:blood / Q000150:complications / Q000628:therapy*
chemical_list: D000596:Amino Acids; D024322:Amino Acids, Aromatic; D000597:Amino Acids, Branched-Chain; D004731:Endotoxins; D015850:Interleukin-6; D011112:Polymyxin B