Implementation of IBD-DCA for ulcerative colitis: a single-institution experience

Ulcerative colitis (UC) is a clinicopathologically challenging diagnosis that greatly impacts patients' quality of life. The recently developed Inflammatory Bowel Disease-Distribution, Chronicity, Activity (IBD-DCA) scoring system offers histopathologists a consistent template to report colonic biopsies from UC patients in a standardised manner. We reviewed the rate of uptake of the IBD-DCA system within our department since its inception in 2022, and statistically correlated our histological findings with the corresponding UC Endoscopic Index of Severity (UCEIS). Of the 449 cases of IBD biopsies reported, 291 were established UC cases. The uptake of the IBD-DCA reporting format reached beyond 95% across all biopsy sites, with noted variation in applying the scoring system to rectal biopsies. Kendall's tau correlation of the 116 UC cases reported in the first six months with their UCEIS revealed a moderate positive correlation between histological activity and all components of the UCEIS (all τ > 0.260, p < 0.05). Possible explanations for histological-endoscopic discrepancies include non-representative endoscopic sampling, differences in detection threshold, and the pan-colonic nature of the UCEIS. We call for the application of the IBD-DCA in future clinical trials to predict possible relapses and guide treatment dosages.