Predictors of 90-Day Colectomy in Hospitalized Patients Receiving Infliximab for Acute Severe Ulcerative Colitis at a Tertiary Care Center

BACKGROUND & AIMS Acute severe ulcerative colitis (ASUC) is a life-threatening presentation of ulcerative colitis requiring prompt treatment. Infliximab (IFX) rescue therapy can prevent colectomy in patients with ASUC. METHODS We performed a cohort study of adult patients hospitalized with ASUC between 01/2014 – 02/2021 who received infliximab rescue therapy. Using multivariable logistic regression, baseline and longitudinal laboratory predictors of colectomy within 90 days of index hospitalization were identified and used to develop a risk prediction model and prognostic scoring system to identifying patients at risk for colectomy. Model performance was assessed using area under the receiver operator characteristic curve (AUC) analysis. RESULTS 166 patients with ASUC who received infliximab rescue therapy were identified. Overall, 24.7% (n=41) underwent colectomy within 90 days. Multivariate analysis revealed that colectomy within 90 days could be predicted by having a calculated IFX clearance of >53L/d (OR 2.28, 95% CI 0.99, 5.22), a day 0 absolute C-reactive protein (CRP) > 91mg/L (OR 3.49, 95% CI 1.58 to 8.08), a decrease in CRP of < 43% from day 0 to day 3 (OR 4.13, 95% CI 1.84 to 9.94), and a decrease in CRP of < 9% from the day of IFX administration to one day post-IFX administration (OR 4.20, 95% CI 1.74 to 10.4). Using these predictors, two highly accurate prognostic scoring system were developed to identify patients at risk for requiring colectomy both prior to administering infliximab (AUC 0.76) and after administer infliximab rescue therapy (AUC 0.81). CONCLUSION We identified important baseline and longitudinal laboratory predictors of colectomy within 90-days among patients with ASUC receiving infliximab rescue therapy and developed accurate prognostic scores to determine risk of colectomy. These scores can be used risk-stratify patients and facilitate personalized management. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: University of Michigan Institutional Review Board waived ethical approval for this work as it a retrospective review of de-identified patient data. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors * ASUC : Acute severe ulcerative colitis ATI : anti-tumor necrosis factor inhibitor CI : Confidence intervals CRP : C-reactive protein EHR : Electronic medical record IV : Intravenous HR : Hazard ratios UC : ulcerative colitis