Clinical association between histological activity at diagnosis and endoscopic response in patients with ulcerative colitis: a retrospective study.

Background: Histological activity in ulcerative colitis (UC) has been accepted to be associated with clinical outcomes. This study aimed to investigate the association between the histological activity at diagnosis and endoscopic findings, either at diagnosis or at the first follow-up, in patients with UC.

Methods: Through a retrospective review of 1 year of medical records, this study evaluated the association between histological and endoscopic activity in 51 patients newly diagnosed with UC at our hospital between March 2015 and February 2022. The Nancy histological index was used to assess histological activity, classifying patients into low (0-2) and high (3-4) groups. The Mayo Endoscopic Subscore and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) were used for endoscopic activity scoring.

Results: At diagnosis, UCEIS demonstrated no statistically significant difference histologically (p=0.065), and histological and endoscopic activities were not significantly correlated (r=0.18, p=0.200). During the first follow-up, 40 patients (78.4%) exhibited low histological activity, and the number of patients with high histological activity decreased after treatment. The first follow-up endoscopy revealed that 30 patients (58.8%) achieved an endoscopic response, including 9 (56.2%) and 21 patients (60.0%) in the high and low groups, respectively, with no significant difference (p=0.800). However, the high group at diagnosis demonstrated a positive correlation with UCEIS endoscopic activity during the first follow-up (r=0.37, p<0.001).

Conclusion: High histological activity at diagnosis was positively correlated with endoscopic activity at the first follow-up. More active care should be provided to patients with high histological activity during diagnosis.