Clinical characteristics and contributors to diagnostic delay in autoimmune gastritis

Abstract Objective To analyze the diagnostic process and clinical characteristics of autoimmune gastritis(AIG) in order to improve the awareness and diagnostic proficiency of this disease. Methods A retrospective cohort study was conducted on 114 patients diagnosed with AIG in Army Medical Center of PLA between January 2021 and June 2024. Comprehensive statistical analysis was performed on clinical data, including demographic characteristics(age, sex), clinical symptoms, comorbidities, diagnostic process, Helicobacter pylori(H. pylori) infection and treatment history, laboratory indicators [results of routine blood test, anemia-related indices, thyroid function, anti-parietal cell antibody(APCA), intrinsic factor antibody(IFA)], and gastrointestinal endoscopic findings(frequency and endoscopic features). Results Among the 114 patients, males accounted for 28.1%(32/114) and females for 71.9%(82/114), and they were at a mean age of 56.3±8.4 years. Predominant symptoms included epigastric/upper abdominal pain(47.4%, 54/114) and postprandial fullness(43.0%, 49/114), while 24.6%(28/114) reported acid reflux or heartburn. Diagnostic delay occurred in 76.4%(87/114) of patients, with a median delay duration of 11.5 months. Primary diagnostic clues were endoscopic reverse gradient atrophy(significantly more severe mucosal atrophy in the gastric corpus/fundus versus antrum; 53.5%, 61/114) and repeated H. pylori eradication failure(≥2 attempts; 22.8%, 26/114). Positivity rate of thyroid peroxidase antibody(TPOAb) and thyroglobulin antibody(TgAb) was 56.9%(33/58) and 36.2%(21/58), respectively. APCA positive rate was 98.8%(81/82), IFA positive rate was 34.1%(28/82), and dual-antibody rate was 32.9%(27/82). Anemia was present in 25.7%(26/101) of the patients. Gastric neuroendocrine tumors(NET) were found in 12.2%(14/114), intraepithelial neoplasia in 5.3%(6/114), and gastric adenocarcinoma in 0.9%(1/114). Among colonoscopy-examined patients, tubular adenomas occurred in 25.0%(13/52) and colorectal malignancies in 3.4%(2/58). There were 18.4%(21/114) patients having gallbladder-related diseases, 7.9%(9/114) having diabetes mellitus, and 1.8%(2/114) of subacute combined degeneration of the spinal cord. Conclusion AIG is frequently associated with diagnostic delay. The reverse pattern of atrophy on endoscopy serves as a critical diagnostic clue, necessitating enhanced recognition in endoscopists. Patients with recurrent H. pylori eradication failure (≥2 attempts) should be evaluated for AIG.