P0260Point-of-care intestinal ultrasound accurately detects endoscopic and histologic activity in patients with ulcerative colitis

Abstract Background Intestinal ultrasound (IUS) is a non-invasive method increasingly used in the management of ulcerative colitis (UC) patients. Our aim was to evaluate the performance of IUS in a point of care setting in extensive and left-sided UC patients. Methods Cross-sectional study, including consecutive adult patients with left-sided (E2) or extensive (E3) UC. IUS features were correlated with established disease targets, including clinical (Simple Clinical Colitis Activity Index (SCCAI), biochemical (fecal calprotectin (FCal) and C-reactive protein (CRP)), endoscopic (Mayo endoscopic subscore) and histologic (Nancy score) activity. IUS activity was assessed by the Milan Ultrasound Criteria (MUC score). Clinical, biochemical, IUS, endoscopic and histologic activity were defined by SCCAI 5, FCal 250 ug/g, MUC 6.2, sMayo 1 and Nancy 0. The most affected segment (excluding the rectum) in endoscopy was considered for the analysis. If the patient was on endoscopic remission, the sigmoid colon was considered. All variables were assessed maximum 1 month apart. Results A total of 84 patients were included (median age 44 (IQR 33-60) years, 37% female, 61% E2), with a median disease duration of 5 years (IQR 2-19). At the time of enrollment, clinical, biochemical, IUS, endoscopic and histologic activity were present at 52%, 50%, 51%, 69% and 80% respectively. The most affected segment in endoscopy and IUS was the sigmoid colon (42% and 48%, respectively) with a moderate agreement (k = 0.48, p 0.001). Severe endoscopic and histologic activity were associated with increased bowel wall thickness (BWT), color Doppler flow (CDF), loss of wall stratification (BWS), loss of haustration and mesenteric fat (p 0.05). The MUC score presented a strong correlation with clinical (SCCAI: r = 0,72, p 0.001, p 0.001) and endoscopic activity (sMayo: r = 0.74, p 0.001) and a moderate correlation with biochemical (FCal: r = 0.51, p 0.001; CRP: r = 0.54, p 0.001) and histologic activity (Nancy: r = 0.59, p 0.001). MUC score presented a high accuracy to assess endoscopic (AUC 0.91 95% CI 0.85-0.97, p 0.001) and histologic activity (AUC 0.84 95% CI 0.75-0.93, p 0.001). A cut-off of 5.6 showed high sensitivity (90%) and good specificity (80%) for identifying endoscopic activity. Although a cut-off of 4.5 yielded very high sensitivity (98%), it demonstrated low specificity (34%) to detect histologic activity. (Table 1) Conclusion In our cohort, IUS showed a high accuracy to identify both endoscopic and histologic activity. The high sensitivity and good specificity observed support the MUC score as a reliable marker of endoscopic activity, while in histologic activity the score performed better as an exclusion tool. Conflict of interest: Dr. Frias Gomes, Catarina: No conflict of interest Bravo, Catarina: No conflict of interest Revés, Joana: No conflict of interest Palmela, Carolina: Other: Consultancy fees from Biocodex, Faes Pharma, Tillots Pharma, Dr. Falk Pharma. Bragança, Sofia: No conflict of interest Rafael, Maria Ana: No conflict of interest Silva, João: No conflict of interest Gloria, Maria Luisa: No conflict of interest Guedes, Ana: No conflict of interest Borralho Nunes, Paula: Personal Fees: MSD Tinoco da Silva Torres, Joana: Grant: Abbvie, Janssen Personal Fees: Pfizer, Janssen, Abbvie, Sandoz, Lilly, Sanofi, Takeda Non-financial Support: Janssen, Abbvie