Histological activity & relapse in UC

Histological activity & relapse in UC

September 20, 2022

Issue 18

Clinical Question

Does histological activity predict clinical relapse in quiescent ulcerative colitis?

Editor’s Bottom Line

Basal plasmacytosis on histology predicts an increased future risk of relapse in patients with ulcerative colitis in clinical remission.


Bessissow T, Kron CM, Marcus V, et al. Impact of Endoscopic and Histologic Activity on Disease Relapse in Ulcerative Colitis. Am J Gastroenterol. Epub ahead of print 2022 Jul 21; https://journals.lww.com/ajg/Abstract/9900.aspx


Between 15–40% of ulcerative colitis (UC) patients who achieve endoscopic healing relapse within 12 months. To identify whether baseline histologic activity predicts relapse, researchers at McGill University prospectively studied 253 UC patients treated at their institution. All participants had achieved clinical remission—defined as a partial Mayo score of 2 or lower and a rectal bleeding score of 0—for at least three months before undergoing a colonoscopy and being followed-up for at least one year.

The authors documented Mayo endoscopic sub-scores and graded histology using the Geboes score, with histologic activity defined as a score ≥3.1. They also documented basal plasmacytosis, which prior research has indicated could be an important histologic indicator of relapse. Disease relapse was defined as a partial Mayo score >2.

None of the participants had a history of surgical resection, none had used corticosteroids within 90 days of study outset or underwent UC medication changes within the three months before study outset. Most patients had left-sided colitis or pancolitis.

During the one-year follow-up, 19% of patients experienced clinical relapse. A baseline Geboes score ≥3.1 did not predict a significantly higher risk of clinical relapse within one year (adjusted Hazard Ratio [aHR]: 1.29; 95% Confidence Interval [CI], 0.67–2.49; p=0.45). However, basal plasmacytosis was linked with a two-fold increased risk of clinical relapse (adjusted Odds Ratio: 2.07; 95% CI, 1.06–4.18, p=0.042). Additionally, those with a Mayo endoscopic sub-score >0 at baseline were significantly more likely than those with a sub-score of 0 to experience clinical relapse during the study (aHR: 2.65; 95% CI, 1.31–5.39; p=0.007).


Study Design: Prospective observational

Funding: None

Allocation: Not applicable

Setting: Single center

Level of Evidence: 1b