Association between autoimmune gastritis and gastric polyps: Clinical characteristics and risk factors.

Background: The relationship between autoimmune gastritis (AIG) and gastric polyps (GPs) is not well understood.

Aim: To explore the clinical characteristics and risk factors of AIG with GPs in patients.

Methods: This double center retrospective study included 530 patients diagnosed with AIG from July 2019 to July 2023. We collected clinical, biochemical, serological, and demographic data were of each patient. Logistic regression analyses, both multivariate and univariate, were conducted to pinpoint independent risk factors for GPs in patients with AIG patients. Receiver operating characteristic curves were utilized to establish the optimal cutoff values, sensitivity, and specificity of these risk factors for predicting GPs in patients with AIG.

Results: Patients with GPs had a higher median age than those without GPs [61 (52.25-69) years vs 58 (47-66) years, P = 0.006]. The gastrin-17 levels were significantly elevated in patients with GPs compared with those without GPs [91.9 (34.2-138.9) pmol/mL vs 60.9 (12.6-98.4) pmol/mL, P < 0.001]. Additionally, the positive rate of parietal cell antibody (PCA) antibody was higher in these patients than in those without GPs (88.6% vs 73.6%, P < 0.001). Multivariate and univariate analyses revealed that PCA positivity [odds ratio (OR) = 2.003, P = 0.017], pepsinogen II (OR = 1.053, P = 0.015), and enterochromaffin like cells hyperplasia (OR = 3.116, P < 0.001) were significant risk factors for GPs, while pepsinogen I was identified as a protective factor.

Conclusion: PCA positivity and enterochromaffin like cells hyperplasia are significant risk factor for the development of GPs in patients with AIG. Elevated gastrin-17 levels may also play a role in this process. These findings suggest potential targets for further research and therapeutic intervention in managing GPs in patients with AIG.