In patients with ulcerative colitis, histologic remission was more predictive of disease relapse compared to endoscopic mucosal healing, suggests a single-center retrospective cohort study published in the Journal of Clinical Gastroenterology.¹

Wang et al selected 74 patients, median age 41 years, with ulcerative colitis for their study who had had the disease for 8 years (median). Their disease was in clinical and endoscopic remission and they underwent a surveillance colonoscopy between 2015 and 2018. Researchers sought to examine if histologic activity could predict disease relapse, the primary endpoint, in patients with endoscopic and clinical remission. Histologic activity was assessed with the Nancy histologic index (NHI) score.

Clinical remission was defined by partial Mayo score (MSp) of 2 or less, while a Mayo endoscopic subscore (MES) of one or less was taken as endoscopic remission. Histologic remission was defined as NHI score of less than 2.

Over the follow-up period of 42 months, 33 out of the 74 patients (45%) relapsed, and had evidence of histologic activity with NHI score of more than one. Only 29% of patients who were in histologic remission at baseline suffered a relapse compared to 64% patients who had some histologic activity at baseline.

On univariate analysis, patients who were in histologic remission and had an MES of 0 had significantly longer relapse-free survival compared to those who had an MES score of 1 and NHI score ranging between 2 and 4, respectively. But on multivariate analysis, a significant association was noted only for histologic activity with a hazard ratio of 4.36.

The NHI score utilizes three histologic criteria namely mucosal ulceration, acute inflammatory cells infiltrate and chronic inflammatory infiltrate to categorize disease activity into five grades of severity.² According to this study, only histologic activity using the NHI score was predictive of future relapse in patients with ulcerative colitis in clinical and endoscopic remission. There is evidence to show that patients with histologic disease are at a greater risk of surgical intervention and hospitalization.³ Hence, the authors suggest that histologic remission “may be a superior therapeutic target than endoscopic remission”.

Reference

1. Wang H, et al. Histologic remission (NANCY Index) is superior to endoscopic mucosal healing in predicting relapse free survival in patients with ulcerative colitis in clinical and endoscopic remission. J Clin Gastroenterol. 2022 Feb 28. doi: 10.1097/MCG.0000000000001681.