LAUSR

INTRODUCTION The fecal immunochemical occult blood test (FIT) and prostaglandin E-major urinary metabolite (PGE-MUM) have been reported to predict the relapse of ulcerative colitis (UC) during remission. In this study, we directly compared FIT and PGE-MUM in predicting relapse and examined the effect of the disease duration on these biomarkers. METHODS Measurements of two biomarkers and endoscopic examination were performed in 73 patients with UC in remission. The patients were followed up for 12 months, and clinical relapse was evaluated. In addition, we divided the subjects into long-term disease duration and short-term disease duration groups for analysis. RESULTS Twenty-one patients (28.8%) relapsed within 12 months. FIT and PGE-MUM levels were significantly higher in the relapsed group than in the remission group. Cut-off values of FIT and PGE-MUM for predicting relapse using receiver operating characteristic (ROC) analysis were 65.0 ng/mL (area under the curve [AUC]: 0.723) and 25.2 µg/g･Cr (AUC: 0.701), respectively. Patients with FIT ≥ 65.0 ng/mL and PGE-MUM ≥ 25.2 µg/g･Cr had a higher risk of clinical relapse. In the short disease duration group, the AUCs of FIT were larger than those of PGE-MUM using ROC analysis, in most instances. In contrast, the AUCs of PGE-MUM were larger than those of FIT in most cases in the long-term disease groups. DISCUSSION FIT and PEG-MUM were highly accurate in predicting clinical relapse in UC patients with short and long disease durations, in remission, respectively.