P0376Intestinal ultrasound activity correlates with IBD-related disability scores in patients with Ulcerative Colitis but not in Crohn’s disease

Abstract Background Patient-reported outcomes and non-invasive monitoring tools play a pivotal role in monitoring inflammatory bowel disease (IBD). The IBD-Disk provides a standardized evaluation of IBD-related disability, a key long-term outcome that captures patients’ functional well-being (1). Intestinal ultrasound (IUS) is a reliable, non-invasive modality to evaluate disease activity in Crohn’s disease (CD) and ulcerative colitis (UC), but its link to patient-reported disability remains uncertain. Methods This retrospective study included IBD patients with paired IUS assessments and IBD-Disk questionnaires completed within one week. UC patients with isolated proctitis were excluded. IUS activity was quantified using the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS), with a cutoff of 23 for UC (2) and 25.2 for CD (3). Statistical analyses included Spearman correlations, Wilcoxon tests, ROC curves, and mixed-effects models. Results Forty-nine UC patients were included (34% female, 71% left-sided colitis, median interquartile range age 37.0 30.0-53.0 years, disease duration 7.0 1.0-12.0 years), with 15 having repeated assessments. UC patients with high IBUS-SAS had significantly higher IBD-Disk scores than those with low IBUS-SAS (p 0.001) (Figure 1). IBUS-SAS correlated moderately with total IBD-Disk (ρ = 0.389, p = 0.006) and most subcomponents (Table 1). Mixed-effects modelling showed a stable association over time (interaction p = 0.89). ROC analysis identified an optimal IBD-Disk cutoff of 41.5 (AUC 0.80, 95% CI 0.66-0.94; sensitivity 79%, specificity 80%). Sublayer analysis showed submucosal thickness correlated with defaecation regulation (ρ = 0.414, p = 0.04), but not with total IBD-disk or other domains. Ninety-seven CD patients were included (54.6% female, 61.9% isolated ileal disease, median age 39.0 27.0-54.0 years, disease duration 8.0 2.0-18.0 years). No significant difference in IBD-Disk scores was found between high and low IBUS-SAS groups (p = 0.06) (Figure 1). IBUS-SAS correlated weakly with total IBD-Disk (ρ = 0.208, p = 0.041), with inconsistent subcomponent correlations (Table 1). ROC analysis showed poor discrimination (AUC 0.62, 95% CI 0.50-0.74; sensitivity 46%, specificity 78%). Conclusion IUS-defined disease activity correlates significantly with patient-reported disability in UC, with stable longitudinal associations, suggesting IUS reflects clinically relevant disease burden and may complement endoscopic and clinical assessments. In CD, this relationship is weaker and inconsistent, likely reflecting heterogeneous clinical presentations and the complex transmural nature of CD, highlighting the need for multimodal assessment tools combining IUS with additional outcome measures to capture disease burden. References: 1. Ghosh S, Louis E, Beaugerie L, Bossuyt P, Bouguen G, Bourreille A, et al. Development of the IBD Disk: A Visual Self-administered Tool for Assessing Disability in Inflammatory Bowel Diseases. Inflamm Bowel Dis. 2017;23(3):333-40. 2. Innocenti T, Rocco C, Balena E, Petrucci G, Lynch EN, Bagnoli S, et al. The use of International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in patients with ulcerative colitis: applicability and comparison with other ultrasound scores. J Crohns Colitis. 2025;19(5). 3. Dragoni G, Gottin M, Innocenti T, Lynch EN, Bagnoli S, Macrì G, et al. Correlation of Ultrasound Scores with Endoscopic Activity in Crohn’s Disease: A Prospective Exploratory Study. J Crohns Colitis. 2023;17(9):1387-94. Conflict of interest: Dr. Eggermont, Elisabeth: I have no conflicts of interest. Lenfant, Matthias: None Ferrante, Marc: Research grants from AbbVie, EG Pharma, Celltrion, Janssen, Pfizer, Takeda and Viatris Consultancy fees from AbbVie, AgomAb Therapeutics, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Janssen-Cilag, MRM Health, Merck Sharp and Dohme, Pfizer, Takeda and ThermoFisher Speakers’ fees from AbbVie, Biogen, Boehringer Ingelheim, Dr Falk Pharma, Ferring, Janssen-Cilag, Merck Sharp and Dohme, Pfizer, Takeda, Truvion Healthcare and Viatris Guedelha Sabino, João: Speaker’s fees: Lilly, Pfizer, Abbvie, Ferring, Falk, Takeda, Janssen, Fresenius, and Galapagos. Consultancy fees: Takeda, Pfizer, Janssen, Ferring, Fresenius, Abbvie, Galapagos, Celltrion, Pharmacosmos, and Pharmanovia. Research support: Galapagos, Viatris, and Eurogenerics. JS is supported by a Senior Clinical researcher grant from the Research foundation – Flanders. Verstockt, Bram: Research support from AbbVie, Biora Therapeutics, Celltrion, Landos, Pfizer, Sanofi, Sossei Heptares/Nxera and Takeda. Speaker’s fees from Abbvie, Agomab, Alfasigma, Biogen, Bristol Myers Squibb, Celltrion, Eli Lily, Falk, Ferring, Galapagos, Materia Prima, Johnson and Johnson, Pfizer, Sandoz, Takeda, Tillots Pharma, Truvion and Viatris. Consultancy fees from Abbvie, Alfasigma, Alimentiv, Anaptys Bio, Applied Strategic, Astrazeneca, Atheneum, BenevolentAI, Biora Therapeutics, Boxer Capital, Bristol Myers Squibb, Domain Therapeutics, Eli Lily, Galapagos, Guidepont, Landos, Merck, Mirador Therapeutics, Mylan, Nxera, Inotrem, Ipsos, Johnson and Johnson, Pfizer, Sandoz, Sanofi, Santa Ana Bio, Sapphire Therapeutics, Sosei Heptares, Takeda, Tillots Pharma and Viatris. Stock options Vagustim and Thethis Pharma.