There are no agreed-upon endoscopic signs for the diagnosis of villous atrophy (VA) in celiac disease (CD), necessitating biopsies 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.

Patients with a clinical indication for duodenal biopsy were prospectively recruited. Six paired NF-white light (NF-WLE) and NF-NBI images with matched duodenal biopsy including the bulb, were obtained from each patient. Histopathology grading used Marsh-Oberhuber classification. A modified Delphi process was performed on images (n=498) and video recordings by 3 endoscopists to define NF-NBI classifiers, resulting in a 3-descriptor classification (villous shape, vascularity, 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.

One hundred consecutive patients were enrolled (n=97 completed the study; 66 females:51.2+/-17.3 years). Thirteen endoscopists evaluated 50-paired NF-WLE/NF-NBI images each (24 biopsy-proven VA). Interobserver agreement among all validators for the diagnosis of villous morphology using the NF-NBI classification was substantial (κ0.71) and moderate (κ0.46) with NF-WLE. Substantial agreement was observed between all 3 NF-NBI Classification descriptors and histology (weighted κ 0.72-0.75) compared with NF-WLE to histology (κ0.34). A higher degree of confidence using NF-NBI was observed when assessing the duodenal bulb.

We have 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 required minimal training.