S1592 Malnutrition Is Associated With Early Colectomy Rates in Patients With Acute Severe Ulcerative Colitis Receiving Infliximab Rescue Therapy

Introduction: Malnutrition is common in patients with acute severe ulcerative colitis (ASUC) and is associated with worse clinical and perioperative outcomes. This study aims to assess the impact of nutritional status on clinical outcomes of hospitalized ASUC patients receiving infliximab (IFX) rescue therapy. Methods: We conducted a retrospective cohort study of hospitalized patients aged ≥17 years old who received IFX rescue therapy for ASUC between 1/2017 and 12/2024 in a single health system. On admission, patients were assessed using the Malnutrition Screening Tool (MST), which assesses body mass index, unintentional weight loss, and poor intake by mouth related to acute illness. Risk for malnutrition (RM) was established by the Registered Dietitian (RD) as low (MST score = 0-1), medium (MST score = 2), or high (MST score ≥3), with higher scores indicating greater malnutrition risk. The primary outcome was short-term colectomy rates based on RM. Subanalyses examined IFX dosing strategy, rates of RD consultation, diet recommendations, and long-term colectomy rates. Results: A total of 69 patients received IFX rescue therapy for ASUC, with 38% identified as high RM (n = 26) and 62% (n = 43) as low or medium RM. No significant differences were observed in baseline C-reactive protein, albumin, or Mayo endoscopic score. Use of standard vs accelerated IFX dosing was similar between groups (P = 0.92). Patients with high RM were more likely to receive RD consultation (P < 0.001), lactose-free diet (P = 0.019) and oral nutrition supplementation (P = 0.035). High RM, compared to low or medium RM, was associated with a significantly increased risk of inpatient colectomy (15% vs 0%, P = 0.017) and 3-month colectomy (23% vs 5%, P = 0.045). Long-term colectomy rates at 6 months (P = 0.16) and 12 months (P = 0.36) were higher in the high RM group, but this was not statistically significant. Conclusion: Patients with ASUC identified as high malnutrition risk had significantly increased inpatient and 3-month colectomy rates after receiving IFX rescue therapy. Optimizing nutritional status early in ASUC hospitalization may improve outcomes and reduce colectomy rates.