Near-focus narrow-band imaging classification of villous atrophy in suspected celiac disease: development and international validation

Background and Aims: There are no agreed-on endoscopic signs for the diagnosis of villous atrophy (VA) in celiac disease (CD), necessitating biopsy sampling for diagnosis. Here we evaluated the role of near-focus narrow-band imaging (NF-NBI) for the assessment of villous architecture in suspected CD with the development and further validation of a novel NF-NBI classification. Methods: Patients with a clinical indication for duodenal biopsy sampling were prospectively recruited. Six paired NF white-light endoscopy (NF-WLE) and NF-NBI images with matched duodenal biopsy sampling including the bulb were obtained from each patient. Histopathology grading used the Marsh-Oberhuber classification. A modified Delphi process was performed on 498 images and video recordings by 3 endoscopists to define NF-NBI classifiers, resulting in a 3-descriptor classification: villous shape, vascularity, and crypt phenotype. Thirteen blinded endoscopists (5 expert, 8 nonexpert) then undertook a short training module on the proposed classification and evaluated paired NF-WLE-NF-NBI images. Results: One hundred consecutive patients were enrolled (97 completed the study; 66 women; mean age, 51.2 +/- 17.3 years). Thirteen endoscopists evaluated 50 paired NF-WLE and NF-NBI images each (24 biopsy-proven VAs). Interobserver agreement among all validators for the diagnosis of villous morphology using the NF-NBI classification was substantial (kappa = .71) and moderate (kappa = .46) with NF-WLE. Substantial agreement was observed between all 3 NF-NBI classification descriptors and histology (weighted kappa = 0.72-.75) compared with NF-WLE to histology (kappa = .34). A higher degree of confidence using NF-NBI was observed when assessing the duodenal bulb. Conclusions: We developed and validated a novel NF-NBI classification to reliably diagnose VA in suspected CD. There was utility for expert and nonexpert endoscopists alike, using readily available equipment and requiring minimal training.

Automated summary

The study developed and validated a novel NF-NBI classification for reliably diagnosing VA in suspected CD, which was found to be useful for both expert and nonexpert endoscopists, utilizing readily available equipment and requiring minimal training.