Abstract:

Objective

Autoimmunegastritis（AIG）isanunderdiagnosed and rare disease. This study aims to summarize the clinical characteristics of patients suspected of AIG through outpatient screening and eventually diagnosed， as well as to stratify patient management to enable personalized follow-up and prevent long-term severe complications that may affect quality of life.

Methods

A retrospective analysis was performed on the clinical data of AIG patients diagnosed via endoscopy at the Endoscopy Center of Tianjin Third Central Hospital between June 2023 and December 2023. Basic information such as gender，reason for consultation， clinical manifestations， and family history were collected， along with laboratory tests including complete blood count， anti-parietal cell antibodies （PCA）， anti-intrinsic factor antibodies（IFA）， thyroid function， gastrin Ⅰ/Ⅱ， G17， folic acid， and vitamin B₁₂ levels. The t-test was used to compare normally distributed quantitative data between two groups， and Fisher's exact test was used for the comparison of categorical data.

Results

A total of 12 patients were diagnosed with AIG through endoscopic screening， with a male-to-female ratio of 1 ∶11 and an average age of 66.08±12.92 years. Three patients（25%） had associated hyperplastic polyps， two patients （16. 7%） had neuroendocrine tumors， and one patient （8. 3%） had early-stage gastric cancer. Seven patients presented with anemia， with an average hemoglobin （Hb） level of （106. 08±30. 85） g/L. The average Hb level in IFA-positive patients was significantly lower than in IFA-negative patients. Thyroid function tests were completed in seven patients，with three cases （42. 9%） showing elevated thyroid-stimulating hormone （TSH）， six cases （85. 7%）positive for thyroid peroxidase antibodies， and five cases （71. 4%） positive for thyroglobulin antibodies.Gastric function tests were completed in nine patients， with abnormal G17 and PGI levels in all cases， and two cases （22.2%） showing abnormal PGII levels.

Conclusion

Among AIG patients diagnosed through combined endoscopy and serology， those in the IFA-positive group are more prone to developing pernicious anemia and associated gastric complications， and therefore require closer attention and follow-up management.

Key words: Autoimmune gastritis, Clinical characteristics, Pernicious anemia, Laboratory tests