Use of the ulcerative colitis endoscopic index of severity and Mayo endoscopic score for predicting the therapeutic effect of mesalazine in patients with ulcerative colitis

Objective: The ulcerative colitis endoscopic index of severity (UCEIS) and the Mayo endoscopic score (MES) are developed as objective methods of evaluating endoscopic severity in patients with ulcerative colitis (UC). The aim of this study is to investigate the diagnostic accuracy of the UCEIS and MES in predicting the patient's response to mesalazine. Methods: Consecutive patients with UC who had undergone colonoscopy within 1 month before starting mesalazine between October 2011 and July 2016 were retrospectively collected at the Department of Gastroenterology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. The median follow-up was 81 months, and all the data were analyzed in January 2021. The primary outcome was the need for step-up treatment, which included the use of corticosteroids, immunomodulatory, or surgery during admission and follow-up. Data were analyzed using the χ2 or Fisher exact test, Spearman test, t-test, and Mann–Whitney U test. Results: Totally, 65 patients were enrolled, of whom 12 (18.5%) needed step-up treatment due to nonresponse to mesalazine. The UCEIS score, MES, and the ulcerative colitis disease activity index (UCDAI) score were significantly higher in patients who had nonresponse to mesalazine (UCEIS score: 6.92 ± 0.69 vs. 4.45 ± 1.17, p