P0411 Utility of Intestinal Ultrasound as a predictor of Severe Ulcerative Colitis response to treatment
Authors: Criado S , Suárez Ferrer C , Poza Cordón J , García-Ramírez L , Rueda García J L , Sánchez Azofra M , Martín Arranz E , María Dolores M A 
Published: January 2025

Background

Severe Acute Ulcerative Colitis (ASUC) is a serious complication of UC that requires an early response to treatment assessment and which clinical and analytical evaluations are often inadequate. In this setting, intestinal ultrasound (IUS) could be helpful, given its accuracy in evaluating inflammatory activity and non-invasiveness. The aim of this study was to determine whether basal IUS findings and index could predict ASUC patients’ response to corticosteroid treatment.

Methods

A retrospective descriptive study was done including ASUC patients admitted to our hospital between January 2019 and January 2024 whose IUS had been performed before corticosteroid treatment. Variables related to clinical and analytical activity at admission and after treatment, corticosteroids response and second-line therapy requirement were also collected. In addition, the need for colectomy during the episode and at 52 weeks of follow-up was analysed.

Results

43 patients were included. Their and IBD baseline characteristics are summarized in Table 1. The 58% (25) of patients responded to corticosteroids. Regarding clinical response, the responders presented lower mean SAI index of 6.6, than non-responders (7.82), finding statistically significant differences (p=0.02). Truelove-Witts severity index was also lower among responders (16.75) than between corticosteroid-refractory patients (18.1), although no statistical significance was observed (p=0.11). Responders showed lower levels of CRP (18.5 mg/L) and FC (2007.5 µg/g) than refractory patients (CRP= 26.2 mg/L, FC=3185.1 µg/g) although the differences found were not significant (CRP, p=0.24; FC, p=0.23). Regarding baseline IUS, the responders had less parietal thickness (5.9 mm) compared to non-responders (5.8 mm), p=0.78. In addition, non-responders obtained major Simple US Score (11.1) than the other group (8.93), finding statistically significance (p=0.04). However, no significant differences (p=0.089) were observed in UCIUS score (responders 8.88, non-responders 8.97) or baseline MUC (p=0.78) between both groups (10.35 responders, 10.2 non-responders).

Conclusion

ASUC-IUS activity is related with corticosteroid clinical and analytical response, which demonstrates the role of IUS in early response to treatment assessment. Having found statistically significance or very close to significance differences with a limited sample size, statistical power and therefore, a greater risk of committing type 2 error make results even more paramount. Therefore, our study shows that IUS is a useful predictor of ASUC response to treatment. We hope that with this evidence the use of IUS monitoring becomes a closer reality to ASUC patients.

References

1.Yuan B, Huang P, Yang M, Tang G, Wang F. Intestinal ultrasound scan predicts corticosteroid failure and colectomy risk in patients with ulcerative colitis. Eur J Gastroenterol Hepatol. 2024 Apr 17. doi: 10.1097/MEG.0000000000002780. Epub ahead of print. PMID: 38652524.

2.de Voogd F, van Wassenaer EA, Mookhoek A, Bots S, van Gennep S, Löwenberg M, et al. Intestinal ultrasound is accurate to determine endoscopic response and remission in patients with moderate to severe ulcerative colitis: a longitudinal prospective cohort study. Gastroenterology 2022; 163:1569–1581.

3.Allocca M, Filippi E, Costantino A, Bonovas S, Fiorino G, Furfaro F, et al. Milan ultrasound criteria are accurate in assessing disease activity in ulcerative colitis: external validation. United European Gastroenterol J 2021; 9:438–442.

4.Bots S, Nylund K, Löwenberg M, Gecse K, D’Haens G. Intestinal ultrasound to assess disease activity in ulcerative colitis: development of a novel UC-ultrasound index. J Crohns Colitis 2021; 15:1264–1271