title: Increased urinary nitric oxide oxidation products in children with active coeliac disease.
abstract: BACKGROUND
  Nitric oxide (NO) production catalyzed by iNOS (inducible NO synthase) is thought to take place mainly in macrophages after activation by inflammatory mediators. NO is subsequently oxidized to nitrite and nitrate, which are excreted in urine. The concentration of inflammatory mediators in small bowel biopsy specimens from patients with coeliac disease is increased. The latter could induce increased NO production by stimulation of intestinal macrophage iNOS, resulting in high levels of urinary NO oxidation products, nitrite and nitrate (NOx).
  
  
  OBJECTIVE
  In the present study we evaluated the urinary NOx/creatinine ratios in children with active coeliac disease (n = 22), coeliac disease patients on a gluten-free diet (n = 9), healthy (n = 11) and sick control children (n = 18).
  
  
  METHODS
  The Griess reagent method was used for measuring urinary NOx.
  
  
  RESULTS
  Median NOx/creatinine ratios of active coeliac disease patients, coeliac disease patients on a gluten-free diet, healthy and sick control patients were 1.21, 0.19, 0.10 and 0.13 mmol/mmol, respectively. All active coeliac disease patients showed increased NOx/ creatinine ratios. Urinary NOx/creatinine ratios of the active coeliac disease patients were significantly higher than those of healthy controls (p < 0.0001), sick controls (p < 0.0001) and coeliac disease patients on a gluten-free diet (p < 0.0001).
  
  
  CONCLUSIONS
  The urinary NOx/creatinine ratio is increased in patients with active coeliac disease and reverts to normal on a gluten-free diet.
authors.affiliation: Department of Pediatrics, University Hospital Maastricht, The Netherlands.
authors.forename: E A
authors.initials: EA
authors.lastname: van Straaten
authors.forename: L
authors.initials: L
authors.lastname: Koster-Kamphuis
authors.forename: I M
authors.initials: IM
authors.lastname: Bovee-Oudenhoven
authors.forename: R
authors.initials: R
authors.lastname: van der Meer
authors.forename: P P
authors.initials: PP
authors.lastname: Forget
mesh_terms: D000293:Adolescent; D002446:Celiac Disease / Q000178:diet therapy / Q000201:enzymology* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D008297:Male; D009566:Nitrates / Q000652:urine*; D009569:Nitric Oxide / Q000652:urine*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D009573:Nitrites / Q000652:urine*
chemical_list: D007070:Immunoglobulin A; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D003404:Creatinine; D019001:Nitric Oxide Synthase