Histologic remission is recommended as an adjunctive treatment target in ulcerative colitis, and scoring systems have been proposed to enhance reproducibility. The Nancy Histologic Index (NHI) is increasingly used in clinical trials; however, its performance in real-world settings is not fully established. This study aimed to assess the interrater reliability (IRR) of the NHI among gastrointestinal pathologists in the United States.
Methods
Thirty-seven whole-slide images of colorectal biopsies from 34 treated ulcerative colitis patients enrolled in a multicenter adult cohort were independently reviewed by 12 gastrointestinal pathologists. Each biopsy was reviewed twice, five months apart, and graded using the NHI. Prior to the second review, pathologists completed an online tutorial on the NHI.
Results
The NHI showed substantial IRR in both reviews [intraclass correlation coefficient (ICC) = 0.79; 95% confidence interval (CI), 0.70–0.87 at Review 1; ICC = 0.78; 95% CI, 0.69–0.86 at Review 2]. However, considerable variability was observed in individual grade assignments, with the lowest IRR for Grade 2 (ICC = 0.24; 95% CI, 0.15–0.37; P < 0.001, and ICC = 0.23; 95% CI, 0.14–0.36; P < 0.001 for Reviews 1 and 2, respectively), followed by Grade 4 (ICC = 0.41; 95% CI, 0.29–0.55; P < 0.001, and ICC = 0.47; 95% CI, 0.35–0.61; P < 0.001). Grade 1 showed the highest IRR (ICC = 0.79; 95% CI, 0.70–0.87; P < 0.001, and ICC = 0.78; 95% CI, 0.69–0.86; P < 0.001). When Grades 2, 3, and 4 (i.e., active disease) were grouped together, the IRR remained substantial across both reviews (ICC = 0.76; 95% CI, 0.66–0.85; P < 0.001).
Conclusions
Our study revealed substantial IRR for active disease (Grades 2, 3, and 4) among 12 pathologists, which underscores the clinical utility of the NHI in the assessment of colorectal biopsies from treated UC patients. However, refinement of the criteria for Grades 2, 3, and 4 may be required to improve reproducibility and enable more accurate monitoring of treatment outcomes in UC, especially as histologic remission is an evolving therapeutic endpoint.
Full text
https://www.xiahepublishing.com/2771-165X/JCTP-2025-00022
The study was recently published in the Journal of Clinical and Translational Pathology .
Journal of Clinical and Translational Pathology (JCTP) is the official scientific journal of the Chinese American Pathologists Association (CAPA). It publishes high quality peer-reviewed original research, reviews, perspectives, commentaries, and letters that are pertinent to clinical and translational pathology, including but not limited to anatomic pathology and clinical pathology. Basic scientific research on pathogenesis of diseases as well as application of pathology-related diagnostic techniques or methodologies also fit the scope of the JCTP.
