Increased urinary F2-isoprostanes in patients with Crohn's disease.

Objectives: Reactive oxygen metabolites have been suggested to participate in the pathogenesis of Crohn's disease, but the evidence supporting this contention in vivo is incomplete. Isoprostaglandin F2alpha type III (iPF2alpha-III, or 15-F2t-IsoP) is a prostaglandin F2alpha isomer produced in vivo by free radical-catalyzed peroxidation of arachidonic acid. We aimed to investigate urinary iPF2alpha-III concentrations as an index of lipid peroxidation in 23 patients with Crohn's disease compared with 23 healthy controls, and to test whether lipid peroxidation correlates to clinical relapse and inflammation.

Methods: Urinary iPF2alpha-III was measured by gas chromatography/electronic impact mass spectrometry.

Results: Urinary iPF2alpha-III concentrations were significantly higher in patients with Crohn's disease than in healthy controls (median [range] = 130 [38-622] vs 91 [35-152] pmol/mmol of creatinine, respectively; p < 0.01). There was a trend toward significance for patients with clinical relapse versus patients with clinical remission (median [range] = 155 [38-622] vs 96 [64-253] pmol/mmol of creatinine, respectively; p = 0.09). A significant correlation was found between urinary iPF2alpha-III and plasma C-reactive protein concentrations, suggesting a link between lipid peroxidation and inflammation.

Conclusion: This study provides evidence of increased lipid peroxidation in patients suffering from Crohn's disease, especially in patients with clinical relapse. iPF2alpha-III quantification has to be investigated as a prognosis biomarker in patients suffering from Crohn's disease.