Morphological features of autoimmune gastritis

Purpose: description and analysis of characteristic morphological criteria of autoimmune gastritis (AIG).
Object and methods. The study included 37 patients diagnosed with AIG who were treated at the clinics of I.M. Sechenov Moscow State Medical University in 2022. During the endoscopic examination, biopsies of the gastric mucosa were taken according to the Sydney protocol. The severity of atrophy was assessed using the OLGA system. Additionally, an immunohistochemical study was performed using antibodies to Chromogranin A (5H7, RU, Leica Biosystems, Germany).
Results. The average age was 59±12.78 years. 97% of the patients (36 out of 37) were female and 3% (1 out of 37) were male. In biopsies of the antrum of the stomach, grade 1 gastritis was detected in 89.2% of patients (33 cases), while in the stomach body, grade 2 gastritis was noted in 78.4% of samples (29 cases) (chi-squared 9.21, p=0.01). A predominance of the metaplastic type of atrophy of the gastric mucosa was noted in the stomach body: complete intestinal metaplasia (IM) was noted in 59% of biopsies (22 cases), incomplete in 2.7% (1 case). Differences in the degree and stage of AIG depending on the localization of gastritis have been established – lesions of 2 or more degrees/stages in the body of the stomach are significantly more frequent (chi-squared 9.21, p=0.01). Additional histological findings were: the presence of hyperplastic polyps of the stomach body in 3 patients (8% of cases), as well as a highly differentiated neuroendocrine tumor of the stomach body (G1) in 1 patient (2.7% of cases).
Conclusion. Histological examination of the fundal part of the stomach typically shows signs of glandular atrophy, widespread pseudopiloric and/or IM, as well as signs of hyperplasia of enterochromaffin-like cells. Reactive changes in the mucous membrane may also be noted in the antral part of the stomach.

1. Lenti M.V., Rugge M., Lahner E., Miceli E., Toh B.H., Genta R.M., et al. Autoimmune gastritis. Nature reviews. Disease primers. 2020;6(1):56. https://doi.org/10.1038/s41572-020-0187-8

2. Song M., Latorre G., Ivanovic-Zuvic D., Camargo M.C., Rabkin C.S. Autoimmune Diseases and Gastric Cancer Risk: A Systematic Review and Meta-Analysis. Cancer research and treatment. 2019;51(3):841-850. https://doi.org/10.4143/crt.2019.151

3. Boeriu A, Dobru D, Fofiu C, Brusnic O, Onişor D, Mocan S. Gastric neuroendocrine neoplasms and precursor lesions: Case reports and literature review. Medicine. 2022;14;101(2):e28550. https://doi.org/10.1097/MD.0000000000028550

4. Kamada T., Maruyama Y., Monobe Y., Haruma K. Endoscopic features and clinical importance of autoimmune gastritis. Digestive endoscopy. 2022;34(4):700-713. https://doi.org/10.1111/den.14175

5. Price A.B. The Sydney System: histological division. Journal of Gastroenterology and Hepatology. 1991;6(3):209-222. https://doi.org/10.1111/j.1440-1746.1991.tb01468.x

6. Rugge M., Correa P., Di Mario F., El-Omar E., Fiocca R., Geboes K., et al. OLGA staging for gastritis: a tutorial. Journal of Gastroenterology and Hepatology. 2008;40(8):650-8. https://doi.org/10.1016/j.dld.2008.02.030

7. Rugge M., Bricca L., Guzzinati S., Sacchi D., Pizzi M.., Edoardo Savarino E, et al. AGA Clinical Practice Update on the Diagnosis and Management of Atrophic Gastritis: Expert Review. Gastroenterology. 2021;161(4):1325-1332.e7. https://doi.org/10.1053/j.gastro.2021.06.078

8. Bockerstett K.A., Petersen C.P., Noto C.N., Kuehm L.M., Wong C.F., et al. Interleukin 27 Protects From Gastric Atrophy and Metaplasia During Chronic Autoimmune Gastritis. Cellular and molecular gastroenterology and hepatology. 2020;10(3):561-579. https://doi.org/10.1016/j.jcmgh.2020.04.014

9. Bettington M., Brown I. Autoimmune gastritis: novel clues to histological diagnosis. Pathology. 2013;45(2):145-9. https://doi.org/10.1097/PAT.0b013e32835cc22c

10. Coati I., Fassan M., Farinati F., Graham D.Y., Genta R.M., Rugge M. Autoimmune gastritis: Pathologist’s viewpoint. World journal of gastroenterology. 2015;14;21(42):12179-89. https://doi.org/10.3748/wjg.v21.i42.12179

11. Losik Y.A., Selivanova L.S., Antonova T.V., Lapina T.L., Tertychny A.S., Ivashkin V.T. Morphological diagnostic criteria of autoimmune gastritis. Russian Journal of Gastroenterology, Hepatology, Coloproctology. 2016;26(5):13-20. (In Russ.)

12. Kiryukh.in A.P., Tertychnyy A.S, Pavlov P.V., Fedorenko A.A., Nagornaya D.P., Marenich N.S., et al. Autoimmune Gastritis: Focus on Endoscopic and Morphological Characteristics. Russian Journal of Gastroenterology, Hepatology, Coloproctology. 2024;34(1):58-69. (In Russ.)

13. Genta R.M., Turner K.O., Robiou C., Singhal A., Rugge M. Incomplete Intestinal Metaplasia Is Rare in Autoimmune Gastritis. Digestive diseases. 2023;41(3):369-376. https://doi.org/10.1159/000527479

14. Kishikawa H., Ojiro K., Nakamura K., Katayama T., Arahata K., Takarabe S., et al. Previous Helicobacter pylori infection-induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication. Helicobacter. 2020;25(1):e12669. https://doi.org/10.1111/hel.12669

15. Pachuashvili N.V., Nagornaya D.P., Tertychnyi A.S. Metachronous tumors of the stomach in a patient with autoimmune gastritis. Arkhiv Patologii. 2023;85(1):57-61. (In Russ.).

16. Vannella L., Lahner E., Osborn J., Annibale B. Systematic review: gastric cancer incidence in pernicious anaemia. Alimentary pharmacology & therapeutics. 2013;37(4):375-82. https://doi.org/10.1111/apt.12177

17. Nagornaya D.P., Sarkisyan S.D., Vasil'eva O.V., Il'icheva K.A., Tertychnyi A.S. Assessment of the content of neuroendocrine cells in the gastric mucosa in patients with autoimmune gastritis. Journal of Anatomy and Histopathology. 2022;11(3):109–113. (In Russ.).