Effect of mucosal healing (Mayo 0) on clinical relapse in patients with ulcerative colitis in clinical remission

Objective: The aim of this study was to identify the effect of mucosal healing (MH) on clinical relapse in patients with ulcerative colitis (UC) who are in clinical remission, with special reference to Mayo endoscopic subscore 0. Methods: Between November 2005 and December 2013, medical records from a total of 215 patients with UC who underwent colonoscopic examination at the time of clinical remission were retrospectively reviewed. Endoscopic MH was defined as a ‘0 point’ of Mayo endoscopic subscore (Mayo 0). Patients were categorized into two groups according to Mayo endoscopic subscore and then analyzed. Results: The baseline characteristics of both groups (MH vs. no-MH), including age at diagnosis, gender, and initial clinical and colonoscopic findings, were not significantly different. The median follow-up duration was 80 (12–118) months. Factors predictive of longer clinical remission duration were age ≥30 years at diagnosis (≥30 years vs. <30 years; hazard ratio [HR] 3.16, 95% CI 1.88–5.30, p < 0.001), shorter interval between diagnosis and clinical remission (<15 months vs. ≥15 months; HR 1.93, 95% CI 1.13–3.28, p = 0.015), and presence of MH at clinical remission (HR 1.95, 95% CI 1.15–3.32, p = 0.014). With a Cox regression model, patients with MH at clinical remission were more likely to have longer duration of clinical remission than patients without MH. Conclusion: The achievement of MH, Mayo 0 in particular, in patients with UC who are in clinical remission is important in predicting a favorable disease course prognosis.