title: Urinary leukotriene E4 excretion: a biomarker of inflammatory bowel disease activity.
abstract: BACKGROUND
  Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory disorders collectively referred to as inflammatory bowel diseases (IBD). Cysteinyl leukotrienes are proinflammatory 5-lipoxygenase-derived products that play a major role in the immune and inflammatory response. Consequently, they may be involved in the pathogenesis of IBD. The aim of this study was therefore to evaluate 1) the urinary excretion of leukotriene E(4) (LTE(4)) in IBD patients and healthy volunteers, and 2) the association between LTE(4) production and the activity (relapse/remission) of the disease.
  
  
  METHODS
  IBD patients and healthy volunteers were prospectively recruited. CD and UC activity was determined on inclusion with the Crohn's Disease Activity Index and Clinical Activity Index, respectively. Urine was collected and the urinary excretion of LTE(4) was measured by liquid chromatography tandem mass spectrometry.
  
  
  RESULTS
  32 CD patients, 28 UC patients, and 30 controls were enrolled in the study. LTE(4) urinary excretion was significantly increased (P < 0.01) in CD [52.0 pg/mg creatinine (10th-90th percentiles: 26.2-148.0)] and UC [64.1 pg/mg creatinine (10th-90th percentiles: 26.7-178.0)] patients compared to controls [32.3 pg/mg creatinine (10th-90th percentiles: 21.8-58.8)]. LTE(4) levels were higher (P < 0.001) in patients with active disease than in patients in remission, for whom the levels of LTE(4) were similar to the levels of controls.
  
  
  CONCLUSIONS
  Cysteinyl leukotriene pathway activation could contribute to the inflammation associated with IBD. The quantification of urinary LTE(4) could be an interesting noninvasive biomarker for the assessment of IBD activity.
authors.affiliation: Laboratory of Pharmacology, Grenoble University Hospital, Grenoble, France. FStanke@chu-grenoble.fr
authors.forename: Françoise
authors.initials: F
authors.lastname: Stanke-Labesque
authors.forename: Joanna
authors.initials: J
authors.lastname: Pofelski
authors.forename: Alexandre
authors.initials: A
authors.lastname: Moreau-Gaudry
authors.forename: Germain
authors.initials: G
authors.lastname: Bessard
authors.forename: Bruno
authors.initials: B
authors.lastname: Bonaz
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine*; D002853:Chromatography, Liquid; D003093:Colitis, Ulcerative / Q000503:physiopathology / Q000652:urine; D003424:Crohn Disease / Q000503:physiopathology / Q000652:urine; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000503:physiopathology* / Q000652:urine; D017999:Leukotriene E4 / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers; D017999:Leukotriene E4