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

Abstract

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 < 0.001; MES: 2.67 ± 0.49 vs. 2.15 ± 0.69, p = 0.024; UCDAI score: 9.33 ± 1.87 vs. 6.70 ± 2.38, p = 0.002). In the multivariate analysis, the UCEIS score (OR = 25.65, 95% CI: 3.048–45.985, p = 0.003), UCDAI score (OR = 1.605, 95% CI: 1.144–2.254, p = 0.006), and C-reactive protein level (OR = 1.056, 95% CI: 1.006–1.108, p = 0.026) were independent risk factors of nonresponse. The area under the ROC curve of UCEIS was 0.95, with a sensitivity of 100% and specificity of 84.6%, a cut-off value of 6, which outperformed the MES with an area under the ROC curve of 0.70. When the UCEIS score ≥6, 60% of patients eventually needed step-up treatment.

Conclusions

The UCEIS is a useful instrument for predicting the therapeutic effect in patients with UC treated with mesalazine. The high probability of mesalazine treatment failure and benefits of other therapies should be discussed in patients with baseline UCEIS score ≥6.