Comparison of the interobserver reproducibility with different histologic criteria used in celiac disease.

Background & Aims: The Marsh–Oberhuber classification
of duodenojejunal mucosal lesions is currently used
for celiac disease. A more simplified classification, which is
based on 3 villous morphologies (A, non-atrophic; B1, atrophic,
villous-crypt ratio <3:1; B2, atrophic, villi no longer
detectable) and an intraepithelial lymphocyte count of
>25/100 enterocytes, has recently been proposed. The aim
of the study was to asses the interobserver agreement between
different pathologists in classifying celiac disease
lesions according to both Marsh–Oberhuber and the new
classification system. Methods: Sixty patients were selected
for the study: 10 subjects without celiac disease, 13
celiac patients with normal villi but a pathologic increase in
intraepithelial lymphocytes >25/100 and hyperplastic crypts,
and 37 patients with celiac disease with villous atrophy. Sixty
slides were sent to 6 pathologists, who were blinded to each
other and were not given any clinical information. Each pathologist
received the set of biopsy specimens on 2 separate
occasions and had to evaluate them according to both grading
systems in a random order. The kappa statistic was used to
assess agreement between each pair of pathologists. Results:
Overall, mean kappa values were 0.35 (fair) for the Marsh–
Oberhuber classification versus 0.55 (moderate) for the new
classification system. Conclusions: The new classification
for duodenal pathology in celiac disease gives better
interobserver agreement compared with the more cumbersome
Marsh–Oberhuber classification and contributes to
the validity of diagnosis in celiac disease.