Unraveling the Mysteries of Autoimmune Gastritis

Abstract

Autoimmune gastritis is an immune-mediated disease characterized by the destruction of parietal cells and atrophy of the oxyntic mucosa due to anti-parietal cell antibodies. It may lead to serious conditions including iron/vitamin B12 and micronutrient deficiencies, neurological disorders, and gastric malignancies. The exact mechanism of this disease is not exactly understood; however, dysregulated immunological mechanisms appear to be major contributors. Patients with this disease are often asymptomatic but may present with gastrointestinal symptoms and/or iron/vitamin B12 deficiencies. Although important serological markers are available and despite advanced endoscopic techniques, the definitive diagnosis relies on histopathological examination of gastric corporal biopsy specimens. Autoimmune gastritis is closely related with increased risk of gastric neuroendocrine tumors and gastric adenocarcinoma. Patients with autoimmune gastritis do not benefit from specific treatments, thus, management is directed to restore micronutrient deficiencies and to prevent occurrence of neoplastic transformation with appropriate endoscopic surveillance.

Keywords: Anti-parietal cell antibody; autoimmune gastritis; gastrin; neuroendocrine tumor type 1.

Figure 1.

Endoscopic view of atrophy of the corpus mucosa showing the absence of rugal folds and submucosal vessels.

Figure 2.

Sticky, dense, adherent mucus is the newest endoscopic finding described in patients with autoimmune gastritis. It is a yellow-to-white mucus that cannot be easily removed from the mucosa with water injection.

Figure 3.

(A) A small neuroedocrine tumor type 1 with erosions on its top is seen in standart white light. (B) The same lesion is demonstrated by linked color imaging, which shows mucosal microstructure irregularities. (C) BLI of the same lesion showing abnormal findings of microstructure ande microvasculature in a close-up view.