Usefulness of Prostaglandin E-Major Urinary Metabolite in Monitoring Crohn's Disease Activity: A Prospective Cross-Sectional Study.

Background: The goal of treatment for Crohn's disease (CD) is to achieve mucosal or transmural healing, and biomarker measurements are useful in monitoring disease activity and guiding treatment. This study aimed to investigate the utility of a new urinary biomarker, prostaglandin E-major urinary metabolite (PGE-MUM), in assessing CD activity.

Methods: The study involved 87 patients with CD who underwent endoscopic examination and measurements of 4 biomarkers: Prostaglandin E-major urinary metabolite, fecal calprotectin (FC), leucine-rich α2 glycoprotein (LRG), and C-reactive protein (CRP). Endoscopic activity was assessed by the Simple Endoscopic Score for Crohn's Disease (SES-CD). Correlations between the CD activity index (CDAI) and SES-CD with the 4 biomarkers were analyzed, and receiver-operating characteristic (ROC) analyses were performed to predict SES-CD ≧ 3.

Results: All 4 biomarkers showed significant correlations with both CDAI and SES-CD. The cutoff (area under the curve [AUC]) values for predicting SES-CD ≥ 3 were as follows: PGE-MUM, 25.2 µg/g Cr (0.800); FC, 257 mg/kg (0.816); LRG, 11.8 µg/mL (0.748); and CRP, 0.22 mg/dL (0.656). Subgroup analysis revealed significant correlations between PGE-MUM and SES-CD in both the L1 (small intestine only) and L2 + L3 (including large intestine) groups, with correlation coefficients of 0.654 and 0.586, respectively. In the L1 group, ROC analysis revealed that, among the 4 biomarkers, PGE-MUM had the highest AUC for predicting SES-CD ≥ 3, with a cutoff (AUC) of 33.1 µg/g Cr (0.861).

Conclusions: PGE-MUM is a biomarker that can reflect endoscopic activity in patients with CD and may be particularly useful in small intestinal lesions.