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 E4 (LTE4) in IBD patients and healthy volunteers, and 2) the association between LTE4 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 LTE4 was measured by liquid chromatography tandem mass spectrometry.Results:
32 CD patients, 28 UC patients, and 30 controls were enrolled in the study. LTE4 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)]. LTE4 levels were higher (P < 0.001) in patients with active disease than in patients in remission, for whom the levels of LTE4 were similar to the levels of controls.Conclusions:
Cysteinyl leukotriene pathway activation could contribute to the inflammation associated with IBD. The quantification of urinary LTE4 could be an interesting noninvasive biomarker for the assessment of IBD activity.