P183 Development of a new simple ultrasound activity score for intestinal Behçet's Disease

Abstract Background Intestinal Behçet's disease (BD) is a relapsing-remitting disease typically associated with punched-out ulcers in the ileocecal region. Optimal monitoring of disease activity is necessary; however, ileocolonoscopy cannot be performed on a regular basis as it is invasive, resource-intensive and causes considerable patient discomfort. Furthermore, there are risks of intestinal bleeding and perforation caused by pretreatment laxatives and air insufflation during the examination. Hence, other follow-up examinations are required. Intestinal ultrasonography (IUS) is a minimally invasive imaging method, but there are no previous reports of comparisons between IUS and endoscopy for intestinal BD. This study aimed to evaluate the usefulness of IUS in assessing the activity of ileocecal ulcers in intestinal BD. Methods This retrospective single-centre study included patients with intestinal BD who underwent colonoscopy and IUS within 2 weeks, from 2007 to 2020. Correlations between the corresponding endoscopic activity using the Sakita–Miwa classification and six IUS variables (bowel wall thickness [BWT], vascularity, bowel wall stratification, intramural and extramural abscesses, fistulas and mesenteric lymphadenopathy) were assessed and used to select the variables that should be included in the new simple score. IUS findings were also compared with biomarker (C-reactive protein [CRP]) concentrations and clinical severity indices (Crohn’s disease activity index and disease activity index for intestinal BD [DAIBD]). Results Seventy-nine IUS examinations from 53 patients were included. Univariate analysis revealed that CRP and DAIBD and the IUS findings BWT, vascularity and bowel wall stratification and intramural and extramural abscesses differed significantly according to endoscopic ulcer activity. Multivariate analysis using a logistic regression model revealed that only BWT and vascularity were statistically different; therefore, a new simple score ([2*BWT] + [5*vascularity]) was constructed. Receiver operating characteristic curve analysis revealed an area under the curve of 0.91 for detecting endoscopic activity, which was superior to those of CRP (0.80; P=0.069), Crohn’s disease activity index (0.69; P=0.002) and DAIBD (0.67; P<0.001). Conclusion A new simple ultrasound activity index for intestinal BD comprising BWT and vascularity was constructed and correlated well with endoscopic disease activity. This is the first report describing the usefulness of IUS for intestinal BD, and we believe the findings will have many implications in clinical practice.