P691 Intestinal ultrasonography accuracy in the evaluation of patients with moderate to severe ulcerative colitis starting infliximab therapy

Abstract

Abstract Background The diagnostic accuracy of detecting active ulcerative colitis (UC) by transabdominal intestinal ultrasonography (IUS) is well described. However, the value of repeated IUS measurements in tight monitoring during treatment remains to be established. The aim of the study is to evaluate the utility of IUS for monitoring biologic therapy in UC. Additionally, to establish the correlations between IUS findings and the endoscopic Mayo score (EMS), as well as clinical and biochemical severity indices. Methods In a prospective open-label study, individuals with moderate to severe ulcerative colitis who were initiating infliximab therapy were included, excluding those with proctitis. Patients were evaluated at baseline and after 3 months of biologics induction by means of clinical, biochemical, endoscopic mayo score, and IUS assessments. A Paired Wilcoxon analysis was conducted to compare data before and after therapy induction. The correlation between bowel wall thickness (BWT) and the endoscopic mayo score (EMS), C-reactive protein (CRP), calprotectin, and the Simple Clinical Colitis Activity Index (SCCAI) was analyzed across both visits. Results Thirty-two patients were enrolled and completed baseline evaluations and 21 completed follow-up assessments. The median age was 38 years (IQR 29-60), with 53% male, a median disease duration of 7 years (6-9), 41% having left-sided colitis, and 59% with pancolitis. All patients were treated with infliximab. No significant differences were observed at both time points in terms of BWT, EMS, CRP, and calprotectin (5.5 vs 4.4, p=0.2; 2 (2-3) vs 2 (1-3), p=0.4; 9.4 vs 9.6, p=0.4; 979 vs 394, p= 0.1, respectively). The only significant improvement was in terms of SCCAI (7 (4.8-8) vs 3 (1-5), p=0.009). BWT showed significant correlations with EMS (r= 0.43, p= 0.0015) (figure 1), CRP (r= 0.40, p= 0.007), and SCCAI (r= 0.28, p= 0.03), while no correlation was found with calprotectin (r= 0.19, p= 0.25). Conclusion Intestinal ultrasonography could serve as a substitute for lower endoscopy in evaluating disease activity.