P1086Splenic parenchymal stiffness measured by shear-wave elastography correlates with the activity of Inflammatory Bowel Disease

Background The etiopathogenesis of inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn’s disease (CD), is multifactorial and still not completely clarified. This results in a lack of a causal therapeutic strategy and a single diagnostic test. There are also no non-invasive indicators available for monitoring the course of the disease that could replace endoscopic examinations. However, a link between the volume of the spleen, which plays an important role in the immune system, and IBD has been suggested. The aim of the pilot study was to evaluate the utility of spleen ultrasound (US) and shear wave elastography (SWE) in assessing IBD activity. Methods The study included 40 patients with IBD (CD n = 12, UC n = 28) treated at the Department of Gastroenterology, Hepatology and Internal Medicine, Institute of Internal Medicine, Wroclaw Medical University. Disease activity in CD was assessed using the Crohn’s Disease Activity Index (CDAI), whereas UC activity was evaluated using the full Mayo score. Fecal calprotectin (FC) level and complete blood count parameters, including platelet count (PC) and plateletcrit (PCT), were taken into account. Patients underwent abdominal ultrasound with measurement of spleen size and volume, as well as assessment of its stiffness using SWE. Results The mean age of the study participants was 44 years (19-76). The median CDAI among patients with CD was 241 points (136-257), and the median Mayo score was 2.5 points (0-10). The median splenic parenchymal stiffness was 20.4 kPa (15.7-33.3), the median FC level was 196 μg/g (20-5000), median PC: 295.5x109/l (194-500), median PCT: 0.295 (0.21-0.47). In the group of patients with IBD, a significant positive correlation was found between PC, PCT, FC, and splenic parenchymal stiffness assessed by SWE (p < 0.05). Among patients with UC, a positive correlation was found between FC level and splenic parenchymal stiffness assessed by SWE (p = 0.01). This correlation was not observed in patients with CD, which may be due to the small size of this subgroup. Conclusion Both systemic and localized inflammatory processes in IBD, reflected by increased PC, PCT, and FC levels, are accompanied by alterations in splenic parenchyma, manifested as increased splenic stiffness on SWE examination. References: 1. Mpakogiannis KC, Fousekis FS, Mpakogianni VC, Mastorogianni IN, Katsanos KH. Evaluating spleen volume in inflammatory bowel disease. Ann Gastroenterol. 2025 Sep-Oct;38(5):465-471. 2. Bayramoglu Z, Akyol Sari ZN, Koker O, Adaletli I, Eker Omeroglu R. Shear wave elastography evaluation of liver, pancreas, spleen and kidneys in patients with familial mediterranean fever and amyloidosis. Br J Radiol. 2021 Dec;94(1128):20210237. 3. Thin LWY, Lawrance IC, Spilsbury K, Kava J, Olynyk JK. Detection of liver injury in IBD using transient elastography. J Crohns Colitis. 2014 Jul 1;8(7):671–7 4. Gros B, Kaplan GG. Ulcerative colitis in adults:a review. JAMA. 2023;330:951–965. doi: 10.1001/jama.2023.15389 5. Loddo I, Romano C. Inflammatory bowel disease:genetics, epigenetics, and pathogenesis. Front Immunol. 2015;6:551. 6. Bronte V, Pittet MJ. The spleen in local and systemic regulation of immunity. Immunity. 2013;39:806–818. Conflict of interest: Dr. Zubkiewicz-Zarebska, Anna: No conflict of interest Gromny, Iga: No conflict of interest Reszczynska, Malgorzata: No conflict of interest Neubauer, Katarzyna: No conflict of interest