de Voogd, FlorisFlorisde Voogdvan Wassenaer, Elsa AElsa Avan WassenaerMookhoek, AartAartMookhoekBots, StevenStevenBotsvan Gennep, SaraSaravan GennepLöwenberg, MarkMarkLöwenbergD'Haens, Geert RGeert RD'HaensGecse, Krisztina BKrisztina BGecse2024-10-112024-10-112022-12https://boris-portal.unibe.ch/handle/20.500.12422/87070BACKGROUND AND AIMS Intestinal ultrasound (IUS) is non-invasive, cost-effective and accurate to determine disease activity in ulcerative colitis (UC). In this study we prospectively evaluated IUS for treatment response in a longitudinal cohort by using endoscopy and histology as gold standards. METHODS Consecutive patients with moderate-to-severe UC (endoscopic Mayo score (EMS)≥2) starting tofacitinib treatment were included. Patients were evaluated at baseline and after 8 weeks of tofacitinib induction by means of clinical, biochemical, endoscopic (EMS and ulcerative colitis endoscopic index for severity (UCEIS)), histological (Robarts Histopathologic Index (RHI)) and IUS assessments. Readers of IUS, endoscopy and histology were blinded for all other outcomes. The primary outcome was difference in bowel wall thickness (BWT) for endoscopic improvement versus no endoscopic improvement. Endoscopic remission was defined as EMS=0, improvement as EMS≤1 and response as a decrease of EMS≥1. RESULTS Thirty patients were included with 27 patients completing follow-up. BWT correlated with EMS (ρ=0.68, p<0.0001), UCEIS (ρ=0.73, p<0.0001) and RHI (ρ=0.49, p=0.002) at both time-points. BWT in the sigmoid was lower in patients with endoscopic remission (1.4mm vs 4.0mm, p=0.016), endoscopic improvement (1.8mm vs 4.5mm, p<0.0001) and decrease in BWT was more pronounced in patients with endoscopic response (-58.1% vs -13.4%, p=0.018). The most accurate cut-off values for BWT were 2.8 mm (AUC:0.87) for endoscopic remission, 3.9 mm (AUC:0.92) for improvement and decrease of 32% (AUC:0.87) for response. The submucosa was the most responsive wall layer. CONCLUSION IUS, importantly BWT as the single most important parameter, is highly accurate to detect treatment response when evaluated against endoscopic outcomes.enintestinal ultrasound monitoring tofacitinib treatment response ulcerative colitis500 - Science::570 - Life sciences; biology600 - Technology::610 - Medicine & healtharticle10.48350/1724373603005610.1053/j.gastro.2022.08.038