Comparison of fecal calprotectin levels and endoscopic scores for predicting relapse in patients with ulcerative colitis in remission

BACKGROUNDAlthough the usefulness of endoscopic scores, such as the Mayo Endoscopic Subscore (MES), Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and Ulcerative Colitis Colonoscopic Index of Severity (UCCIS), and biomarkers such as fecal calprotectin (FC) for predicting relapse in ulcerative colitis (UC) has been reported, few studies have included endoscopic scores for evaluating the entire colon.AIMTo compare the usefulness of FC value and MES, UCEIS, and UCCIS for predicting relapse in patients with UC in clinical remission.METHODSIn total, 75 patients with UC in clinical and endoscopic remission who visited our institution between February 2019 and March 2022 were enrolled. The diagnosis of UC was confirmed based on the clinical presentation, endoscopic findings, and histology, according to the current established criteria for UC. Fecal samples were collected the day before or after the colonoscopy for measurement of FC. Endoscopic evaluations were performed using MES, UCEIS, and UCCIS. The primary outcome measure of this study was the assessment of the association between relapse within 12 mo and MES, UCEIS, UCCIS, and FC. The secondary outcome was the comparison between endoscopic scores and biomarkers in enrolled patients with UC with mucosal healing.RESULTSFC and UCCIS showed a significant correlation with UCEIS (r = 0.537, P < 0.001 and r = 0.957, P < 0.001, respectively). Receiver-operating characteristic analysis for predicting MES 0 showed that the area under the curve of UCCIS was significantly higher than that of FC (P < 0.01). During the 1-year observation period, 18 (24%) patients experienced a relapse, and both the FC and UCCIS of the relapse group were significantly higher than that of the remission group. The cut-off values for predicting relapse were set at FC = 323 mg/kg and UCCIS = 10.2. The area under the curve of the receiver-operating characteristic analysis for predicting relapse did not show a significant difference between FC and UCCIS. The accuracy of the endoscopic scores and biomarkers in predicting relapse was 86.7% for UCCIS, 85.3% for UCEIS, 76.0% for FC, and 73.3% for MES.CONCLUSIONThe three endoscopic scores and FC may predict UC relapse during clinical remission. Among these scores, UCEIS may be the most useful in terms of ease of evaluation and accuracy.