Multimodal dynamic ultrasound approach as predictor of response in patients with Crohn's disease treated with ustekinumab.

Background: The approval of ustekinumab (UST) has opened new options for the treatment of Crohn's disease (CD), but potential markers predicting the efficacy of this interleukin-12/23 inhibitor are lacking. Contrast-enhanced ultrasound (CEUS) is non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment induction. Objectives: We conducted a prospective monocentric study aiming to explore the value of multimodal intestinal ultrasound (IUS) in predicting the response to UST in patients with active CD who have been previously exposed to anti-tumour necrosis factor α (TNFα). Design and methods: Consecutive patients with moderate-to-severe CD involving the terminal ileum who were scheduled to begin UST therapy were enrolled between January 2020 and October 2021 in the inflammatory bowel diseases outpatient centre. A complete IUS evaluation, including B-mode, Doppler, dynamic CEUS and elastography, was performed at the time of induction (T0) and after 8 (T1), 16 (T2), 24 (T3) and 48 (T4) weeks of therapy. Each IUS parameter and their variations from baseline were correlated with endoscopic response and mucosal healing after 1 year. Results: A total of 52 patients were included, 29 (55.8%) of which reached endoscopic response at T4. The univariate analysis revealed that, between T3 and T0, the percentage changes of bowel wall thickness, Limberg score, mean signal intensity, rise time, wash-in rate, C reactive protein and Harvey-Bradshaw Index were associated with long-term therapeutic outcome. Based on the above parameters, we developed an IUS score that showed a good performance in predicting 1 year-endoscopic response (area under the curve: 0.91). Conclusion: Multimodal ultrasound could be helpful to predict long-term therapeutic outcome in patients with CD treated with UST. Registration: NCT05987501.