Abstract
BACKGROUND AND AIMS: A reduction of bowel wall thickness (BWT) on intestinal ultrasound (IUS) predicts endoscopic response in ulcerative colitis (UC). Advanced techniques such as shear-wave elastography (SWE) might enhance response assessment. We aimed to identify early IUS parameters to predict treatment response to filgotinib in UC. METHODS: This prospective observational study included UC patients with endoscopically active disease (endoscopic Mayo score [EMS] ≥2, extending beyond the rectum) starting on filgotinib. IUS parameters, including SWE, were assessed at baseline (T0), week 4 (T1), and at second endoscopy (T2). EMS of both the most-affected segment and the sigmoid was assessed at T0 and T2, and endoscopic response was defined a ≥1 point decrease in EMS. RESULTS: A total of 23 patients were included. Six of 21 patients who underwent a second endoscopy were endoscopic responders. At T1 in the sigmoid, a BWT decrease of ≥1.33 mm or ≥24.7% (odds ratio [OR]: 32.5 [2.4-443.2], P = .009 and OR: 13.8 [1.2-156.6], P = .035) and submucosa decrease of ≥20.8% (OR: 13.8 [1.2-156.6], P = .035) predicted endoscopic response. Additionally, color Doppler signal (CDS) improvement at T1 predicted endoscopic response (OR: 20.0 [1.7-241.7], P = .018). In the sigmoid, SWE values changed differently over time between responders and non-responders (T2: 9.9 ± 15.7 vs -8.1 ± 11.4 kPa, P = .002). However, SWE values at T1 were not predictive of endoscopic response (OR: 1.07 [0.99-1.16], P = .088). CONCLUSIONS: On IUS, BWT, submucosal thickness, and CDS predict endoscopic response after 4 weeks of filgotinib treatment. SWE values in the sigmoid differ between responders and non-responders, but early assessment does not predict treatment response.