To explore the clinical and endoscopic features of patients with autoimmune gastritis (AIG) and to improve the accuracy of clinical diagnosis of AIG.

From January 3, 2020 to November 25, 2021, the general information (gender, age), laboratory examination indicators and endoscopic findings of 179 AIG patients diagnosed at the Second Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. The laboratory examination indicators included hemoglobin, gastrin-17, pepsinogen (PG), anemia combination indicators (ferritin, vitamin B₁₂), thyroid function indicators (thyroid-stimulating hormone, thyroglobulin antibody and thyroid peroxidase antibody), Helicobacter pylori, and anti-parietal cell antibody and anti-intrinsic factor antibody. Descriptive methods were used for statistical analysis.

Among the 179 AIG patients, there were 42 males (23.5%) and 137 females (76.5%), with an average age of (55.23±12.04) years old. The gastrin-17 level of AIG patients was 195.31 ng/L (143.64 ng/L, 273.61 ng/L), PG Ⅰ level and PG Ⅰ/PG Ⅱ ratio were 12.40 μg/L (7.65 μg/L, 19.40 μg/L) and 1.03 (0.66, 1.52), respectively. There were 15.3% (18/118) of the AIG patients with iron deficiency anemia, and 16.1% (19/118) with megaloblastic anemia. The positive rate of anti-parietal cell antibody was 71.8% (51/71), and the positive rate of anti-intrinsic factor antibody was 25.4% (18/71). The serum thyroid-stimulating hormone level increased in 27.3% (15/55) of the patients, and the positive rates of thyroglobulin antibody and thyroid peroxidase antibody were 31.6% (12/38) and 47.4% (18/38), respectively. The positive rate of Helicobacter pylori was 29.7% (38/128). The endoscopic appearance of AIG indicated reverse atrophy, characterized by obvious atrophy in gastric fundus and gastric body mucosa, however the atrophy of gastric antrum was not obvious. Under endoscopy yellow-white turbid mucus, which was difficult to be washed, was found in 67.0% (120/179) of the patients, and under endoscopy the residual gastric fundus glands could be seen in 19.6% (35/179) of the patients. Among 179 AIG patients, 7 cases (3.9%) of neuroendocrine tumor (NET), 7 cases (3.9%) of early gastric adenocarcinoma (including 1 case of poorly differentiated adenocarcinoma), 1 case (0.6%) of adenoma, and 14 cases (7.8%) of hyperplastic polyps were found. Except for the case of poorly differentiated adenocarcinoma undergoing surgery, the others were treated with endoscopic resection.

When unexplained iron deficiency anemia, megaloblastic anemia, or reverse atrophy is found, AIG should be considered. AIG patients are at high risk for gastric cancer and NET, and should be closely followed up, and active treatment should be given before anemia and neurological symptoms appear.

Autoimmune gastritis; Autoimmune disease; Anemia; Neuroendocrine tumors