P747 Predictors of thiopurine treatment failure in ulcerative colitis

Abstract

Background/Aaims Immunomodulators such as azathioprine (AZA) and 6-mercaptopurine (6-MP) have been used for induction and maintenance treatment of Ulcerative colitis (UC) for several decades. In non-responsive patients to thiopurines (AZA or 6-MP), biologic agents or surgical treatment could be considered. This study was to evaluate the predictive factors of response to AZA/6-MP in patients with moderate to severe UC. Methods Among total 254 patients who were managed as UC in Korea University Ansan Hopital through 2005 to 2015, 113 patients were enrolled in this study. The patients' medical records including baseline characteristics, disease extension of UC, severity, treatment agents, and surgical treatments were reviewed retrospectively. Univariate and multivariate analyses were conducted to evaluate the predictive factors of clinical response to immunomodulators. Results Among 113 patients with UC, who received AZA/6-MP treatment, 37 patients (32.7%) failed thiopurine treatment (19 treated with steroids, 14 treated with anti-TNF alpha, 4 treated with surgical treatment). Between two groups(treatment failure and sustained response) according to AZA/6-MP treatment, AZA/6-MP treatment was used more frequently in patients with ulcerative pancolitis. The disease extension was significantly different between two groups. Multivariate analysis revealed that the disease extension were significantly associated with AZA/6-MP treatment failure. Conclusions AZA/6-MP treatment is effective on induction and maintenance treatment in UC. However, early biologic treatment should be considered in extensive UC, since their AZA/6-MP treatment is less effective.