Urinary leukotriene E4 excretion: a biomarker of inflammatory bowel disease activity.
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.
Stanke-Labesque
Françoise
F
Laboratory of Pharmacology, Grenoble University Hospital, Grenoble, France. FStanke@chu-grenoble.fr
Pofelski
Joanna
J
Moreau-Gaudry
Alexandre
A
Bessard
Germain
G
Bonaz
Bruno
B
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
D015415:Biomarkers; D017999:Leukotriene E4