Differences in image-enhanced endoscopic findings between Helicobacter pylori-associated and autoimmune gastritis

Abstract
Background and study aims The aim of this study was to elucidate the differences in image-enhanced endoscopy (IEE) findings between Helicobacter-pylori-associated and autoimmune gastritis. Patients and methods Seven H. pylori-naïve, 21 patients with H. pylori-associated gastritis and seven with autoimmune gastritis were enrolled. Mucosal atrophy in the corpus was evaluated using autofluorescence imaging and classified into small, medium and large. In a 2 × 2-cm area of the lesser curvature of the lower corpus, micromucosal pattern was evaluated by magnifying narrow band imaging and proportion of foveola (FV)- and groove (GR)-type mucosa was classified into FV > 80 %, FV 50 % to 80 %, GR 50 % to 80 %, and GR > 80 %, then a biopsy specimen was taken. Results Fifteen of 21 (71 %) H. pylori-associated gastritis patients exhibited medium-to-large atrophic mucosa at the corpus lesser curvature. All autoimmune gastritis patients had large atrophic mucosa throughout the corpus (P < 0.001). All H. pylori-naïve patients had the FV > 80 % micromucosal pattern. Nineteen of 21 (90 %) H. pylori-associated gastritis patients had varying proportions of GR- and FV-type mucosae and five of seven (71 %) autoimmune gastritis patients showed FV > 80 % mucosa (P < 0.001). Compared with patients who were H. pylori-naïve, patients with H. pylori-associated and autoimmune gastritis exhibited a higher grade of atrophy (P < 0.001), but only patients with H. pylori-associated gastritis showed a higher grade of intestinal metaplasia (P = 0.022). Large mucosal atrophy with FV > 80 % micromucosal pattern had sensitivity of 71 % (95 % CI: 29 %–96 %) and specificity of 100 % (95 % CI: 88 % to 100 %) for diagnosis of autoimmune gastritis. Conclusions IEE findings of the gastric corpus differed between H. pylori-associated and autoimmune gastritis, suggesting different pathogenesis of the two diseases. Received: 07 July 2020 Accepted: 21 September 2020 Publication Date: 01 January 2021 (online) © 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany