Xanthine oxidase activity and blood glutathione redox ratio in infants and children with septic shock syndrome.
OBJECTIVE
The possible role of xanthine oxidase (XO) activation in the signal transduction process during the septic shock syndrome was examined. The XO activity index after caffeine intake was assessed simultaneously with the blood glutathione redox ratio, a known parameter of oxidative stress.


METHODS
An investigational clinical study in a nine-bed pediatric intensive care unit.


METHODS
Critically ill infants and children (n = 34) with systemic inflammatory response syndrome following infection, trauma or major surgery. Biochemical investigations (n = 54) were performed at various stages of the shock syndrome, characterized by pediatric risk of mortality and organ dysmetabolic scores. Controls consisted of 30 healthy children.


RESULTS
The in vivo XO activity index was measured as the urinary ratio of two metabolites of caffeine: 1-methyluric acid and 1-methylxanthine. The blood concentrations of oxidized (GSSG) and reduced glutathione (GSH) were determined. The XO activity index and redox ratio GSSG/GSH were highly increased in patients in shock dominated by the clinical symptoms of a proinflammatory response. A significantly lower XO activity index was found with an increased GSSG/ GSH in patients whose stage of shock was characteristic of an excessive anti-inflammatory response. The XO activity index and GSSG/ GSH were correlated closely with each other (r = 0.624, n = 54; p < 0.001), and were also related to the daily severity scores.


CONCLUSIONS
Potent and simultaneous activation of the two redox systems strongly indicates a definite role of free radicals from XO in the overspill of the acute proinflammatory reaction of the shock syndrome, followed by a significant downregulation.
Németh
I
I
Department of Pediatrics, Medical Faculty of Szeged University, Hungary.
Boda
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D015415:Biomarkers; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005978:Glutathione / Q000097:blood*; D006801:Humans; D007223:Infant; D008297:Male; D009102:Multiple Organ Failure / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018709:Statistics, Nonparametric; D018746:Systemic Inflammatory Response Syndrome / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000652:urine*
D015415:Biomarkers; D014969:Xanthine Oxidase; D005978:Glutathione