P0538 Histologic remission predicts relapse in patients with Ulcerative Colitis

Background

Histologic remission is not currently established as a formal treatment target in ulcerative colitis (UC). However, growing evidence indicates that histologic activity is associated with increased rates of relapse, hospitalization, and colectomy1.

We aimed to evaluate the predictive value of histologic remission in UC patients and its potential role in guiding disease management.

Methods

A unicentric retrospective study was conducted, including all patients with UC who achieved endoscopic remission (Mayo Endoscopic Subscore ≤1) on colonoscopy between January 2020 and June 2023. Histologic remission was defined as the absence of neutrophils in the lamina propria or epithelium. Clinical activity was assessed using patient reported outcomes (PRO-2) for stool frequency or rectal bleeding (PRO-2>0). Clinical relapse was defined as the need for therapy optimization, switching therapy, or corticosteroid use.

Factors associated with relapse were assessed using chi-square tests for categorical variables and t-tests for continuous variables. A binary logistic regression model was applied to further evaluate these associations.

Results

A total of 90 patients were included (58% male; mean age: 55 ± 15 years), with a median disease duration of 15±9 years. Among patients in endoscopic remission, 61% had a Mayo endoscopic subscore of 0, and 39% had a score of 1. Histologic remission was observed in 74% of patients (table 1).

During follow-up, 23% (n=21) of patients experienced a relapse. Histologic activity was statistically associated with a higher risk of clinical relapse (p=<0.001). No differences were found in relapse rates between patients with Endoscopic Mayo Subscores of 0 or 1 (p=0.073). Younger age (p=0.009), shorter disease duration (p=0.002), and previous failure of advanced therapies (p=0.049) were also associated with a higher risk of clinical relapse. Multivariate analysis identified histologic remission as the sole independent predictor of relapse (odds ratio: 0.173, 95% CI: 0.053–0.571, p=0.004).

Conclusion

These observational data suggest that histologic remission may predict clinical relapse in patients with UC. In this cohort, histologic remission was identified as the sole predictor of relapse, outperforming endoscopic remission.

References

Lobatón T, Bessissow T, Ruiz-Cerulla A, De Hertogh G, Bisschops R, Guardiola J, Van Assche G, Vermeire S, Ferrante M. Prognostic value of histological activity in patients with ulcerative colitis in deep remission: A prospective multicenter study. United European Gastroenterol J. 2018 Jun;6(5):765-772. doi: 10.1177/2050640617752207.