Uncontrolled clinical activity and anti-TNF plus thiopurine combination therapy are predictive factors of 1-year infection risk following acute severe ulcerative colitis: AOCC and ANZIBDC collaboration study.

Abstract

Background: Information on infectious complications following acute severe ulcerative colitis (ASUC) is limited. The aim of this study was to determine rates of infections following ASUC treatment and the associated risk factors, using data from the Asian Organization for Crohn's and Colitis (AOCC) and the Australia New Zealand IBD Consortium (ANZIBDC). Method(s): We collected medical records of patients diagnosed with ASUC according to Truelove and Witts criteria from January 2015 to December 2022 across the AOCC and ANZIBDC. We analyzed the incidence, prognosis, and associated risk factors for infection within one year after treatment and discharge for ASUC. Result(s): A total of 676 ASUC patients (mean age 37+/-17.08, male 379, 56%) were enrolled, with 329 from AOCC (China, Japan, Korea, Taiwan) and 347 from ANZIBDC. Infections occurring within 1 year following ASUC treatment were identified in 65 patients (9.6%), with no difference between the AOCC and ANZIBDC groups. The most common infections included Clostridioides difficile (C. diff) infection (17/65, 26%), CMV colitis (14/65, 21%), and pneumonia (7/65, 10%). The infection group experienced a poorer prognosis, including a higher overall readmission rage (39.3% vs. 92.2%, P < 0.001) and UC-related readmission rate (16.3% vs. 31.3%, P = 0.004), as well as increased mortality during the 1-year follow-up period (1.1% vs. 13.8%, P < 0.001) compared with the non-infection group. Infections occurred more frequently in patients with clinical activity than in those with clinical remission following ASUC treatment (17.2% vs. 6.9%, P < 0.001). In an analysis adjusted for age, gender, and region (AOCC vs. ANZIBDC), significant risk factors for infection after ASUC included combination therapy with an anti-TNF agent and thiopurine at discharge (adjusted hazard ratio [aHR] 3.714, 95% confidence interval [CI] 1.122-8.979, P = 0.03) and clinical activity during the follow-up period (aHR 3.080, 95% CI 1.690-5.614, P < 0.001). Conclusion(s): Infections were common within 1 year following ASUC treatment and associated with high readmission rates and increased risk of mortality. Combination therapy with an anti-TNF agent plus thiopurine at discharge and persistent disease activity were significant risk factors for the development of infection following ASUC treatment. These findings highlight the need for vigilant infection monitoring and inflammation control to improve ASUC outcomes.