title: Spontaneous bacterial peritonitis results in oxidative and nitrosative stress in ascitic fluid.
abstract: OBJECTIVE
  Spontaneous bacterial peritonitis (SBP) is a major complication of liver cirrhosis and accounts for significant mortality. Although oxygen free radicals and nitric oxide been implicated in the pathophysiology of liver cirrhosis, information on their role during the development of SBP is scarce. This study examined these active species in ascitic fluid from patients with SBP, and in response to treatment.
  
  
  METHODS
  Forty-nine consecutive patients with cirrhosis and ascitic fluid neutrophil counts less than 250/cumm were studied as controls. Another 21 patients whose ascitic neutrophil count exceeded 250/cumm were treated as cases. Ascitic fluid was collected from these patients at entry and 48 h after treatment with antibiotics. Nitrate and markers of oxidative stress such as malondialdehyde, protein carbonyl content and total and protein thiols were measured.
  
  
  RESULTS
  A significant increase in malondialdehyde and protein carbonyl levels was seen in ascites from patients with SBP when compared to controls. This was accompanied by a decrease in total thiols and protein thiols. In addition, there was a significant increase in ascitic fluid nitrate in patients with SBP when compared to control patients. After antibiotic treatment, malondialdehyde, protein carbonyl and nitrate levels dropped back towards control values, and total thiols also recovered.
  
  
  CONCLUSIONS
  This study demonstrated the presence of oxidative stress in ascitic fluid from patients with SBP, and showed that ascitic fluid nitrate may be a marker for diagnosing SBP and a useful index in determining therapeutic response to antibiotic treatment.
authors.affiliation: The Wellcome Trust Research Laboratory, Department of Gastrointestinal Sciences, Christian Medical College, Vellore, India.
authors.forename: Sathish Kumar
authors.initials: SK
authors.lastname: Natarajan
authors.forename: Ashis
authors.initials: A
authors.lastname: Mukhopadhya
authors.forename: Anup
authors.initials: A
authors.lastname: Ramachandran
authors.forename: Sophia
authors.initials: S
authors.lastname: Amalanathan
authors.forename: George
authors.initials: G
authors.lastname: Kurian
authors.forename: Kunissery A
authors.initials: KA
authors.lastname: Balasubramanian
mesh_terms: D001202:Ascitic Fluid / Q000378:metabolism*; D001424:Bacterial Infections / Q000378:metabolism*; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008103:Liver Cirrhosis / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010538:Peritonitis / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism
chemical_list: D011506:Proteins; D009569:Nitric Oxide