Early thiopurine maintenance is associated with reduced proximal disease progression and colectomy rate in ulcerative colitis

Background Thiopurines effectively maintain remission in ulcerative colitis patients. Whether early initiation of thiopurines after ulcerative colitis diagnosis decreases proximal disease progression and colectomy rates is not known. Methods We conducted a cohort study of ulcerative colitis subjects recruited from 1970 to 2009. Early thiopurine maintenance was defined as commencement of azathioprine or mercaptopurine within 5 years of diagnosis and maintenance for at least 6months. Propensity score matching was conducted to correct for confounders influencing early thiopurine introduction. Outcomes of interest were colectomy rate and endoscopic proximal disease extension. Results 982 consecutive ulcerative colitis subjects (12879 patient-years) were recruited with 116 requiring colectomy. Thiopurines initiation and maintenance increased over time with median time to thiopurine commencement decreasing from 23years in the first decade to 2 years in the last decade (P< 0.0001). Multivariate analysis showed that early thiopurine maintenance significantly decreased the need for colectomy [hazard ratio, 0.13; 95% confidence interval (CI):0.03-0.55; P=0.006]. The number of subjects needed to be treated to reduce one colectomy at 5 and 1 Oyears was 18 (95% CI, 1636) and 12 (95% CI, 11-25). After propensity score matching, early thiopurine maintenance was significantly associated with decreased colectomy (hazard ratio, 0.10; 95% CI, 0.03-0.43; P=0.002) and proximal progression of disease extent (hazard ratio, 0.26; 95% CI, 0.10-0.78; P=0.015). Conclusion Early thiopurine maintenance for >6months is significantly associated with reduced colectomy and proximal progression of disease extent in ulcerative colitis.Copyright (C) 2021 Wolters Kluwer Health, Inc. All rights reserved.