P484 Intestinal Ultrasound Can Detect Active Inflammation In Inflammatory Bowel Disease Patients Despite Combined Clinical And Biomarker Remission

Abstract

Abstract Background Intestinal ultrasound (IUS) has only recently been implemented in the USA for inflammatory bowel disease (IBD) monitoring. Colonoscopy is considered the gold standard for evaluation of inflammation but may not be feasible for every assessment due to cost, time, and accessibility. Clinical activity scores and biomarkers are used instead as adjunct measures of disease. Since IUS incurs low cost and time with easy accessibility, our study aimed to demonstrate the utility of incorporating IUS into IBD practice by evaluating the sensitivity and specificity of these adjunct measures of inflammation and the impact of decisions made based on IUS. Methods This retrospective cohort analysis evaluated patients with IBD at our institution who underwent IUS from July 2020 to May 2021. The patients were reviewed for repeat IUS visits until July 2022. Patients received IUS regardless of clinical or biomarker remission, and/or if they were able to receive a colonoscopy. Clinical remission was defined as UCAI ≤ 5 and partial Mayo ≤ 2 or HBI ≤ 5. Biomarker remission was defined as ESR ≤ 40 mm/hour; CRP ≤ 8 mg/L; FCP ≤ 125 mg/mg; and fecal lactoferrin ≤ 30 mcg/mL. Combined remission was defined as both clinical and biomarker remission. The sensitivity and specificity of these groups was evaluated based on IUS. Treatment plans were decided based on IUS findings. Patients with normal IUS maintained therapy while those with positive findings required a change/escalation of therapy. These patients had repeat IUS to ensure the changes resulted in reduction of inflammation. Results In 148 total patients receiving IUS, 62% (N=92) had active disease. Clinical remission (figure 1) was 41% sensitive and 75% specific while biomarker remission was 49% sensitive and 58% specific to IUS findings. When combined (clinical + biomarker remission), sensitivity increased to 62% and specificity decreased to 52% (figure 2). There was a total of 39 repeat ultrasounds. Inflammation was improved at repeat IUS, measured by a decrease in overall bowel wall thickness in 77% (30/39) patients for a mean of 0.121 cm. Vascular flow improved in 79% (15/19) of patients with abnormal Doppler at initial IUS by a mean of 0.65, and mural stratification improved in 80% (20/25) of patients with mural disruption at initial IUS. Conclusion Our study showed that even when combining biomarker results and clinical scores, the sensitivity for detecting inflammation was 62%. Additionally, as demonstrated by the improvement in inflammation at IUS follow up, clinical decisions based on IUS results effectively reduced inflammation in IBD patients. As such, IUS is necessary in the management of IBD to effectively identify and treat patients with masked inflammation.