S808 Level and Change of CRP Are Associated With 30-Day Risk of Colectomy in Patients Hospitalized With Acute Severe Ulcerative Colitis Receiving Infliximab

Abstract

Introduction: Infliximab (IFX) has been efficacious in reducing colectomy rates among patients with moderate-to severe ulcerative colitis, but predictors of colectomy within 30 days of IFX among patients with acute severe ulcerative colitis (ASUC) are less established. Methods: We performed a single-center retrospective analysis of patients who received at least one dose of IFX while admitted between 2011-2022. We assessed demographic, clinical and laboratory predictors of colectomy within 30 days of first IFX dose. Multivariable and time-to-event analysis using Kaplan-Meier with log-rank statistics were used to assess risk factors for colectomy within 30 days. Results: A majority of the 172 patients hospitalized with ASUC who received IFX received 10 mg/kg (87.79%). Overall, 22/172 patients (12.79%) underwent colectomy within 30 days of first IFX dose. On univariable analysis, age, sex, race, ethnicity, BMI and smoking status were not associated with risk of colectomy. Higher initial CRP was significantly associated with 30-day risk of colectomy (106.17 vs. 65.10 mg/dL among patients who did not undergo colectomy; p< 0.01), as was a decrease of CRP ≤50% prior to discharge (p< 0.01). Lower initial albumin [< 3 (36.36%), 3.0-3.5 (40.91%), >3.5 g/dL (22.73%)] was associated with our primary outcome (p=0.046), as was a higher number of bowel movements in a 24-hour period prior to discharge (5.6 vs. 3.9 among patients who did not undergo colectomy; p=0.0256). On multivariable analysis, higher initial CRP (aOR 1.01, 95% CI 1.00 – 1.02), ≤50% change in CRP after first dose of IFX (aOR 9.00, 95% CI 2.43 – 33.29) and higher number of bowel movements in a 24-hour period prior to discharge (aOR 1.24, 95% CI 1.01– 1.52) remained significantly associated with risk of colectomy when adjusting for relevant covariables (Table). On Kaplan-Meier analysis, initial CRP >100 mg/dL, albumin < 3 g/dL and change in CRP ≤50% prior to discharge were significantly associated with decreased time to colectomy (Figure). Conclusion: Among patients with ASUC, higher CRP, decrease of CRP ≤50% and higher number of bowel movements prior to discharge were associated with increased risk of colectomy within 30-days of receiving IFX. Initial CRP >100 mg/dL, albumin < 3 g/dL and decrease of ≤50% in CRP prior to discharge were associated with decreased time to colectomy. These results can identify patients at highest risk and impact clinical decision-making regarding need for and timing of colectomy in patients with ASUC receiving IFX.Figure 1.: Kaplan–Meier curve showing estimates of proportion of patients requiring colectomy within 30 days of first infliximab dose (A) comparing patients with albumin on admission < 3 g/dL and albumin on admission ≥ 3 g/dL (p=0.0488) and (B) comparing patients with CRP on admission > 100 mg/dL and CRP on admission ≤ 100 mg/dL (p<0.01). Table 1. - Multivariable Analysis Examining Predictors of Colectomy within 30 Days Among Patients Hospitalized with Acute Severe Ulcerative Colitis Receiving Infliximab. *p=0.015; **p<0.01; ***p=0.036 Variable adjOdds Ratio (95% Confidence Interval) Disease Duration (years) 0.95 (0.86 – 1.04) Family history of IBD No Reference Yes 0.53 (0.10 – 2.79) Extent of disease on admission Proctitis/Left sided colitis Reference Not documented 0.13 (0.01 – 2.04) Pancolitis 1.30 (0.35 – 4.85) GI infection No Reference Yes 2.13 (0.51 – 8.91) CRP on admission (mg/dL)* 1.01 (1.00 – 1.02) Serum albumin on admission >3.5 g/dL Reference 3-3.5 g/dL 1.83 (0.47 – 7.12) < 3 g/dL 3.77 (0.79 – 18.07) Percent change in CRP after first infliximab dose** >50% decrease Reference ≤50% decrease 9.00 (2.43 – 33.29) Number of bowel movements in 24-hour period prior to discharge*** 1.24 (1.01– 1.52)