P0421 INSPIRE: INtestinal ultraSound Parameters for Identifying steroid non-response in patients with acute seveRE ulcerative colitis

Abstract Background Intestinal ultrasound (IUS) is increasingly used for non-invasive assessment of ulcerative colitis (UC). Its role in predicting corticosteroid response in acute severe UC (ASUC) is not well established. The INSPIRE study aimed to identify early IUS parameters associated with steroid non-response in ASUC. Methods In this prospective study, adults admitted with ASUC (per Truelove and Witts criteria) underwent IUS on admission (T1) and 48±24 hours later (T2). Parameters assessed included bowel wall thickness (BWT), submucosal thickness (SMT), and Milan Ultrasound Criteria (MUC). Steroid non-response (SNR) was defined as the need for medical rescue therapy (MRT). Logistic regression and ROC analyses identified predictive thresholds. Results Twenty patients were included, median age 33 years (IQR 25.5-46), 50% were female. All had left-sided or pancolitis, and in 90% the sigmoid colon was the most severely affected segment. Ten (50%) patients required MRT. On univariable analysis, T1BWT, T1SMT, T2BWT and T2SMT were predictors of SNT. Doppler, stratification and haustrations were not predictive. Non-responders had greater T1BWT (5.6 vs 4.4mm, p