P0502 Impact of Endoscopic and Histologic Activity on Disease Relapse in Ulcerative Colitis: 3-year and 5-year follow-up
Authors: Abbas A , Ching Hui Yee C , Zoughlami A , Lakatos P , Bitton A , Wild G , Afif W , Bessissow T 
Published: January 2025

Abstract

Background
Endoscopic healing in patients with ulcerative colitis predicted higher rates of clinical remission at 12 months follow-up. Meanwhile, active histologic disease did not affect time to clinical relapse in patients with UC who achieved endoscopic remission while the presence of basal plasmacytosis was associated with relapse. [1] We aim to evaluate the impact of baseline endoscopic and histological healing on long-term clinical relapse as well as the rates of UC-related emergency room (ER) visits, hospitalizations and surgery.

Methods
This prospective observational study was conducted at the Inflammatory Bowel Disease (IBD) Centre of McGill University Health Centre (MUHC) July 2012 to July 2020 and included all adult UC patients undergoing a colonoscopy with biopsies for disease assessments. Patient must have been in clinical remission with a stable dose of medication for at least 3 months prior to enrolment. Patients were followed every 3 months in the first year then every 6-12 months to assess disease relapse, defined as a partial Mayo score (PMS) &gt;2. Active endoscopic disease was defined as Mayo endoscopic score (MES) of 2 or 3. Active histological disease was defined as a Geboes score ≥3.1 (epithelial neutrophils with or without crypt destruction/erosions).

Results
A total of 253 patients were included in this study. At the 3-year follow-up, baseline active endoscopic and histological disease did not predict clinical relapse. However, baseline endoscopy with a EMS of 0 (compared to 1-3) showed a trend towards significance in predicting relapse (P = 0.08). Multivariate analysis adjusting for age, gender, height, and smoking status remained non-significant (P = 0.0837, 95% CI 0.29–1.08). At 5 years, baseline histological activity did not predict risk of clinical relapse, however, endoscopy with EMS 0 significantly predicted clinical relapse (P = 0.0080), with multivariate analysis confirming this (P = 0.0110, 95% CI 0.27–0.84). Baseline endoscopy with EMS 1-3 was linked to increased ER visits at 3 years (P = 0.02), but not at 5 years (P = 0.7618). Histological disease activity was not linked to increased ER visits at 3 and 5 years. Neither baseline endoscopy nor histology predicted the risk of hospitalisation or surgery at either follow-up (P &gt; 0.05).

Conclusion
Active histologic disease did not predict long-term clinical relapse at 3- or 5-years point. On the other hand, baseline endoscopic activity of EMS of 0 compared to 1-3, only predicted clinical relapse at 5 years and IBD-related ER visits at 3 years. This long-term follow up data questions the additional role of histology in patient with complete endoscopic healing.

References
1.Bessissow T, Kron CM, Marcus V, Lemieux C, Laneuville J, Afif W, Wild G, Lakatos PL, Brassard P, Bitton A. Impact of Endoscopic and Histologic Activity on Disease Relapse in Ulcerative Colitis. Am J Gastroenterol. 2022 Oct 1;117(10):1632-1638. doi: 10.14309/ajg.0000000000001912. Epub 2022 Jul 21. PMID: 35862833.