P642 Impact of histological and endoscopic remission in clinical recurrence and recurrence-free time in ulcerative colitis

Abstract

Background: Resolution of clinical symptoms and mucosal healing constitute the therapeutic goals in ulcerative colitis (UC). Although a Mayo Endoscopic subscore (MSe) of 0 is the optimal target, there is insufficient information to recommend it for all patients and a MSe of 1 should be a minimum target. Moreover, histological healing is not a target in UC because of limited evidence for its clinical utility in UC. This study aims to determine the impact of the definition of endoscopic remission (MSe 0–1) and histological activity in the recurrence of UC and the time free of recurrence. Methods: Patients with UC in clinical remission (partial Mayo Score [MSp]≤1) and endoscopic remission (MSe≤1) who underwent colonoscopy with biopsies between 03/2010–12/2013 were included. The validated Nancy score was used to evaluate histological activity, which considers inactivity if 0–1 and activity if 2–4. The recurrence-free time was evaluated and recurrence was defined as MSp≥2, therapy to induce remission, hospitalisation or colectomy. Predictive factors associated with recurrence were determined. Statistical analysis: X2, Student's t-test, Kaplan-Meier survival curves, Log-rank test, logistic regression and Cox regression. Significance: p<0.05. Results: Sixty patients were included, 58.3% (n=35) were women, with a mean age of 52.7 years. MSe=0 was observed in 53.3% (n=32) and MSe=1 in 46.7% (n=28). Histological activity occurred in 61.7% (n=37). Clinical recurrence occurred in 31.7% (n=19) of patients, with a cumulative risk of 17.1%/24.5%/26.7%/40.1% at 12/24/36/48 months, respectively. MSe=1 (p=0.02) and histological activity (p=0.007) were significantly associated with recurrence. Of these, only histological activity (p=0.03) was an independent predictive factor of recurrence. Patients with MSe=1 (p=0.02) and with histological activity (p=0.01) had a significantly shorter recurrence-free time in univariate analysis. In multivariate analysis, only histological activity (p=0.02) was an independent predictive factor of lower recurrence-free time. Conclusions: Patients with UC in clinical and endoscopic remission experienced a global recurrence of 31.7% (n=19), reaching 40.1% in 48 months. The presence of histological activity represents an independent predictive factor of recurrence and time to recurrence, which was not verified with MSe 0–1.