Prevalence and clinical and endoscopic features of newly diagnosed autoimmune gastritis

Aims Prevalence, clinical and endoscopic features of newly diagnosed AIG.

Methods Single center retrospective observational study. Patients with positive parietal cell autoantibodies (PCA) (≤ 1/160) with gastroscope between 2013 and 2023 were considered. Patients without biopsies according to Sydney’s protocol or Helicobacter infection were excluded. Four different histological stages were defined; stage 0 (potential AIG) without chronic gastritis or atrophy, stage I or chronic gastritis, stage II or atrophic gastritis and stage III (complicated) whenever dysplasia, NET or gastric adenocarcinoma were detected.

Results During this period a total of 50000 gastroscopes were performed. 426 patients fulfilled were included, 316 females (74.4%) and the median age 54.4 years (IQR 45,3-63,2). The estimated prevalence for GAI was 0.9% (IC 95% 0.8%-1%). One-hundred patients (23,7%) presented a title of PCA 1/160, 151 patients (35.5%) 1/320, 111 patients (26,1%) 1/640 and 64 patients (15%) 1/1280. 151 patients presented at least another autoimmune disorders (35.5%), where autoimmune hypothyroidism was the most frequent (18.7%). Most frequent associated symptoms were dyspepsia in 149 patients (35%) followed by vitamin B12 deficiency in 141 patients (33.º%).

Endoscopically 33 patients presented antral and corporal endoscopic signs of atrophy (8.1%), 57 patients presented corporal and fundic atrophy (13.9%), 36 patients (8.8%) antral, corporal and fundic atrophy while 69 patients presented exclusively corporal atrophy (16.9%). 39 patients exhibited hyperplastic polyps (9.2%), 8 patients fundic gland polyps (1.9%), 3 adenomas with low grade dysplasia (0.7%) and 2 patients presented neuroendocrine tumours (0.5%). Additionally, 2 patients were diagnosed with gastric adenocarcinoma (0.5%), one patient classified as T1N0M0 and the second patient as T4N0M0. Histologically, 105 patients were classified as potential AIG (24.7%), 99 patients as stage I (23,2%), 215 patients as stage II (50.5%) and 7 patients as stage III (1.6%). At the gastric body, 139 patients presented intestinal metaplasia (32.6%), 29 patients pseudopyloric metaplasia (6.8%) and 28 patients intestinal and pseudopyloric metaplasia (6.6%). Metaplasia was less frequent at the gastric antrum, as 49 patients presented intestinal metaplasia (11.5%), one patient pseudopyloric metaplasia (0.2%) and another patient intestinal and pseudopylori metaplasia (0.2%). The presence of intestinal/pseudopyloric metaplastic changes was more frequent in advanced stages (73.9% vs 26.1%; RR 2.8 (95% CI; 2.15-3.6, p<0.001). Low grade dysplasia without visible lesions were detected in 3 patients.

Conclusions Around 1 percent of patients presented AIG, and more than fifty percent exhibited histological signs of atrophy gastritis.

Publication History

Article published online:
27 March 2025