Interobserver agreement in the assessment of gastritis reversibility after Helicobacter pylori eradication

AIM: Our aim was to determine interobserver agreement in the application of the Sydney system to assess reversibility of gastritis after Helicobacter pylori eradication. METHODS AND RESULTS: Forty-three patients with a Helicobacter pylori-positive duodenal ulcer disease were included in the study. All patients included had successful H. pylori eradication after different antimicrobial drug combinations. Biopsy samples were collected from antrum and body, according to the Sydney recommendations, before antimicrobial therapy, 2 months after and at yearly intervals during 2-4 years of follow up. Three pathologists, who were blind to clinical data, evaluated histological changes in 221 antral and 219 body specimens stained with haematoxylin and eosin and with Warthin Starry. The percentage of pairwise agreement, kappa and weighted kappa statistic were used. Agreement in recognizing the presence of H. pylori colonization of the gastric mucosa, activity of inflammation and intestinal metaplasia was over 90%. Agreement in recognizing chronic inflammation in the body and atrophy in the antrum was between 78 and 89% respectively. The kappa values were excellent (more than 0.75) for the grade of H. pylori in the body, good (between 0.50 and 0.75) for the grade of H. pylori in the antrum, grade of inflammatory activity and intestinal metaplasia in the antrum and moderate to good (0.38-0.53) for the grade of chronic inflammation. Kappa values were poor to good (from 0.17 to 0.57) only in evaluation of the grade of atrophy. CONCLUSION: Interobserver agreement in the application of the Sydney system to reversibility of gastritis after H. pylori was good. More strict criteria should be used for atrophy and to differentiate normal and mild chronic inflammation.