ObjectiveTo describe the clinical characteristics of patients with autoimmune gastritis (AIG), and to further explore the clinical differences between AIG patients with positive Helicobacter pylori ( H. pylori) and with negative H. pylori, and to reveal the significance of H. pylori in AIG patients.

MethodsFrom January 1, 2020 to December 31, 2023, 112 patients visited Taizhou Hospital of Zhejiang Province who underwent endoscopy examinations and AIG-related antibody tests were retrospectively enrolled. Among them, 34 cases were complicated with H. pylori infection ( H. pylori-positive group) and 78 cases were not complicated with H. pylori infection ( H. pylori-negative group). Anemia status, the positive rates of AIG antibodies including anti-parietal cell antibody (PCA) and intrinsic factor antibody (IFA), gastric function markers such as gastrin-17, pepsinogen Ⅰ (PGⅠ) and the ratio of PGⅠ to PG Ⅱ, vitamin B12 and folic acid levels, as well as the manifestations under gastroscopy, thyroid function indicators, and results of thyroid ultrasound examination were comparatively analyzed between H. pylori-positive group and H. pylori-negative group. Independent samples t-test, Mann-Whitney U test, and chi-square test were used for statistical analysis.

ResultsAmong the 112 patients with AIG, 30 cases were males and 82 cases were females, with the age of (59.3±10.1) years old. Twenty-three (20.5%) AIG patients were complicated with iron deficiency anemia and 13 (11.6%) AIG patients were complicated with megaloblastic anemia. The proportion of patients complicated with megaloblastic anemia of H. pylori-positive group was higher than that of H. pylori-negative group (23.5%, 8/34 vs. 6.4%, 5/78), and the difference was statistically significant ( χ ²=5.20, P=0.023). The positive rates of PCA, IFA, thyroid peroxidase antibody, and thyroglobulin antibody were 98.2% (110/112), 27.5% (28/102), 75.0% (24/32), and 62.5% (20/32), respectively. The gastrin-17 level of 94.2% (97/103) AIG patients was more than 5 times the normal upper limit; and the vitamin B12 level of 24.4% (22/90) AIG patients decreased. There were 84.0% (42/50) of AIG patients complicated with thyroid nodules or echo changes under ultrasound, and 18.8% (12/64) of AIG patients had thyroid function changes. In addition to reverse atrophy under endoscopy, yellow-white turbid mucus was found in 51.8% (58/112) AIG patients, 51 cases (45.5%) combined with proliferative polyps, 8 cases (7.1%) combined with gastric neuroendocrine tumors and 7 cases (6.2%) combined with gastric adenoma or adenocarcinoma. The proportion of patients with adenoma or adenocarcinoma in H. pylori-positive group was higher than that of H. pylori-negative group (14.7%, 5/34 vs. 2.6%, 2/78), and the difference was statistically significant ( χ ²=4.07, P=0.044).

ConclusionsWhen unexplained anemia occurs clinically, inverse atrophy or gastric neuroendocrine tumors presented under endoscopy, positive gastric autoantibodies detected, the diagnosis of AIG should be considered. The eradication of H. pylori still remains as the key to the treatment of AIG patients.