Prostaglandin E-major Urinary Metabolite as a Biomarker for Pediatric Ulcerative Colitis Activity.

Objectives: Prostaglandin E-major urinary metabolite (PGE-MUM) is a useful biomarker for adult ulcerative colitis (UC) activity. In the present study, we evaluated whether PGE-MUM can also be a biomarker of pediatric UC activity and compared its efficacy in predicting UC activity with that of C-reactive protein and erythrocyte sedimentation rate. Methods: Twenty-nine pediatric patients with UC (8-18 years) and 29 healthy age-and sex-matched subjects were enrolled. UC activity was evaluated using the Pediatric Ulcerative Colitis Activity Index, highest Mayo endoscopic scoring (Mayo), and Matts grading (Matts) for histologic scoring, and the sum of Mayo (total of 6 segments) and Matts in all patients with UC. PGE-MUM levels were measured using a radioimmunoassay. Results: PGE-MUM levels were elevated in endoscopically and histologically active UC patients, but not in patients with endoscopic and histologic remission or controls. PGE-MUM levels positively and significantly correlated with UC activity. PGE-MUM levels were positively correlated with Pediatric Ulcerative Colitis Activity Index (r = 0.594), highest Mayo (r = 0.462), the sum of Mayo (r = 0.694), and the sum of Matts (r = 0.613), but not with highest Matt (r = 0.352). The sum of Mayo and the sum of Matts, which reflect total colon inflammation, showed highest correlation with PGE-MUM. C-reactive protein levels did not correlate with any UC activity scores. Erythrocyte sedimentation rate exhibited correlation (r = 0.490) with the sum of Mayo only. Conclusions: PGE-MUM is a reliable biomarker that reflects both the endoscopic and histologic activity of the entire colon in pediatric UC.