Prostaglandin E-Major Urinary Metabolite Predicts Relapse in Patients With Ulcerative Colitis in Clinical Remission

INTRODUCTION: Prostaglandin E-major urinary metabolite (PGE-MUM) is a novel biomarker reflecting endoscopic activity in ulcerative colitis (UC). However, there are no studies investigating the efficacy of PGE-MUM as a biomarker for predicting relapse. We investigated whether PGE-MUM can predict clinical relapse of UC. METHODS: The measurement of PGE-MUM and endoscopic evaluation were performed in 70 patients with UC in clinical remission. The optimal cutoff values predicting relapse and relapse-free rate were analyzed. RESULTS: Sixteen patients (22.9%) relapsed during the 12-month follow-up. The median PGE-MUM value of relapsed patients at entry was significantly higher than that of patients in clinical remission (P = 0.008). The cutoff value of PGE-MUM predicting future relapse was 25.2 μg/g Cr by receiver-operating characteristic (ROC) analysis, and the area under the ROC curve was 0.721 (95% confidence interval: 0.556–0.886). The relapse-free rate of patients with PGE-MUM ≥25.2 μg/g Cr was significantly lower than that in patients with PGE-MUM <25.2 μg/g Cr (log-rank test: P < 0.001). The ROC analysis of UC patients with disease duration more than 1–8 years showed that duration of more than 5 years had the largest area under the ROC curve 0.821 (95% confidence interval: 0.583–1.000) and that the optimal cutoff value was 26.3 μg/g Cr. DISCUSSION: PGE-MUM is a reliable biomarker for predicting future relapse, particularly in UC patients with long-disease duration.