Intestinal Ultrasound Findings and Their Prognostic Value in Early Crohn's Disease - a Copenhagen IBD Cohort Study.

Abstract

Background and aims: We characterize the sonographic features of Crohn's disease at diagnosis and evaluate the prognostic value of intestinal ultrasound during the early stage of disease.

Methods: A prospective, population-based cohort of patients with newly diagnosed Crohn's disease were followed with intestinal ultrasound in conjunction with symptomatic, biochemical, and endoscopic evaluations.

Results: Between May 2021 and April 2023, 201 patients with adult-onset Crohn's disease were recruited. No associations were found between sonographic inflammation at diagnosis and diagnostic delay. After three months, transmural remission was achieved in 38% of patients, with colonic disease patients achieving transmural remission more often. Transmural remission at three months was significantly associated with steroid-free clinical remission at three months and all subsequent follow-ups within the first year. Transmural remission was also associated with a lower risk of treatment escalation during follow-up until 12 months (26% vs. 53%, p=0.003). At 12 months, 41% had achieved transmural remission. Higher baseline body mass index negatively impacted the likelihood of 12-month transmural remission significantly (overweight: [OR 0.34 (0.12; 0.94)], obese: [OR 0.16 (0.04; 0.73)]). The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in the terminal ileum at diagnosis was the best predictor of ileocecal resection during the first year, with an optimal threshold of 63 (AUC 0.92, sensitivity 100%, specificity 73%).

Conclusions: Transmural remission is an achievable outcome target for many newly diagnosed Crohn's disease patients and is associated with a favorable clinical outcome, including sustained steroid-free clinical remission. Further, intestinal ultrasound findings at diagnosis predict future ileocecal resection.