The ulcerative colitis endoscopic index of severity is useful to predict medium- to long-term prognosis in ulcerative colitis patients with clinical remission

Background: The ulcerative colitis endoscopic index of severity [UCEIS] is a validated scoring system. Nevertheless, few studies have investigated its usefulness in clinical settings. In this study, we aimed to predict the clinical prognosis of patients with ulcerative colitis [UC] in clinical remission using the UCEIS. Methods: A total of 285 UC patients who underwent a colonoscopy between April 2012 and March 2013 were enrolled. We reviewed clinical characteristics and endoscopic scores at the time of the colonoscopy and checked the clinical remission rate of the patients until September 2015. Clinical remission and recurrence were defined as a partial Mayo score of =1 and =3, respectively. Results: UCEIS was strongly correlated with the Mayo endoscopic score [r=0.93], moderately correlated with clinical severity [r=0.64] and mildly correlated with C-reactive protein [r=0.34]. The recurrence rate increased gradually as it became more endoscopically severe [5.0% for UCEIS=0, 22.4% for UCEIS=1, 27.0% for UCEIS=2, 35.7% for UCEIS=3 and 75.0% for UCEIS=4-5] in patients with clinical remission. UCEIS and the concomitant use of thiopurine were independent factors predicting clinical recurrence. A multivariate analysis indicated that the absence of bleeding [p=0.001] and the absence of mucosal damage [p < 0.001] in a colonoscopy were independent factors for prolongation of clinical remission. Conclusion: The UCEIS is useful to predict the medium- to long-term outcomes of UC patients with clinical remission. The absence of bleeding or mucosal damage is important for maintaining clinical remission.