Correlation between endoscopic healing and histological healing of ulcerative colitis determined using the Mayo score

Abstract

Mucosal healing (MH) is thought to be the endpoint of therapy in patients with ulcerative colitis (UC) . Endoscopic mucosal healing is currently considered as an optimal indicator of mucosal healing, however, it is still not clear whether endoscopic mucosal healing concurs with histological mucosal healing. We investigated the correlation between endoscopic healing and histological healing using Mayo endoscopic subscores and Sandborn’s histological scores, and also comparatively investigated the incidence of relapse of UC in patients with endoscopic MH and histological MH. Fifty patients with UC underwent complete colonoscopy by the same endoscopist, and each of seven colonic segments were evaluated prospectively using the Mayo endoscopic subscores (grade 0-3) . Biopsies were also performed in the same colonic segments and evaluated by the Sandborn’s histology scores (grade 0-4) . Endoscopic MH was defined as Mayo score 0 or 1, and histological MH was defined as Sandborn’s score 0 or 1. Relapse was defined as recurrence of overt hematochezia. Endoscopic MH was found in 93.4%, and histologic MH in 82.2% of the total of 350 colonic segments. Among all the segments showing endoscopic MH, 85.6% also showed histological MH, while the remaining 14.4% showed histological active inflammation. Of 37 patients with endoscopic MH, the incidence of relapse was higher in the histological non-MH patients (30.8%) than in the histological MH patients (12.5%) . No cases of relapse were found among the patients with a histological score of 0 in all the colonic segments, whereas 18% of those with a histological score of 1 in any of the colonic segments developed relapse. There was a dissociation between endoscopic and histological mucosal healing, and histological mucosal healing may represent true healing rather than endoscopic mucosal healing, and may need to be considered as the ultimate goal of treatment in patients with UC.