In Japanese patients with type A gastritis with pernicious anemia the condition is very poorly associated with Helicobacter pylori infection

Endoscopic features and clinical importance of autoimmune gastritis

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B₁₂ , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

Autoimmune Gastritis With Progression of Leukemic Non-Nodal Mantle Cell Lymphoma

The pathogenesis of autoimmune gastritis (AIG) remains unclear. In addition, it is difficult to follow the process of AIG onset endoscopically. Leukemic non-nodal mantle cell lymphoma (MCL) was newly added as a subtype of MCL in the fourth revised edition of the World Health Organization (WHO) classification (2017). Here, we report a case of AIG associated with the progression of leukemic non-nodal MCL. A 74-year-old woman who had been followed up in a nearby hospital for chronic B-cell lymphoproliferative disorder with no treatment for six years presented with fever and fatigue in the previous one month. The patient was admitted to our department and was diagnosed with leukemic non-nodal MCL. Positron emission tomography-computed tomography examination, which indicated no abnormalities in the six preceding years, revealed uptake in the bone marrow and spleen. Since MCL was progressing, esophagogastroduodenoscopy (EGD), which showed almost no abnormal findings in the gastric mucosa 13 preceding months, was conducted again to search for lesions involving gastrointestinal MCL. Lymphoma lesions were not found, but wide atrophic mucosal changes in the stomach were revealed mainly in the corpus, and patchy redness was also observed in the pylorus, consistent with AIG. The patient tested positive for an anti-gastric parietal cell antibody (×80), her gastrin level was significantly elevated (5,280 pg/mL), and her pepsinogen (PG) I/PG II was considerably less than 1.0 (>3.1). Although no pathological confirmation was obtained by biopsy, the patient was clinically diagnosed with AIG. In our patient, AIG was revealed to be associated with the progression of leukemic non-nodal MCL in this short period.

Multicenter study of autoimmune gastritis in Japan: Clinical and endoscopic characteristics

BACKGROUND AND AIM

In Japan, the prevalence of autoimmune gastritis (AIG) is assumed to be very low. With the recent rapid decrease in Helicobacter pylori (Hp) prevalence, reports on AIG are increasing. This multicenter registry study aimed to clarify the characteristics of AIG, especially its endoscopic appearance.

METHODS

A total of 245 patients with AIG from 11 institutions in Japan from January 2010 to October 2016 were included, and their clinical and endoscopic findings were evaluated.

RESULTS

Mean age was 67.2 ± 11.4 years, and 63.7% of the participants were women. The most common approach to diagnose AIG was endoscopic examination. Repeated incorrect treatment for Hp infection, due to a false-positive result in ¹³ C-urea breath test, ranked third among the basis for diagnosis of AIG. Associated gastric lesions were type 1 neuroendocrine tumor (11.4%), adenocarcinoma (9.8%), and hyperplastic polyps (21.1%). Corpus pan-atrophy was the most common appearance (90.1%); however, remnant oxyntic mucosa was found in 31.5% of the patients (flat, localized type, 48.6%). Sticky adherent dense mucus and scattered minute whitish protrusions were also observed in approximately 30% of the patients. Despite the prevailing presumption of the antral mucosa remaining normal, 42.3% of the patients presented with various extents of atrophy, and patchy redness and circular wrinkle-like patterns were both observed in approximately 20% of the patients.

CONCLUSIONS

The present study showed some prominent clinical characteristics and endoscopic findings of AIG. We believe that our study will facilitate the diagnosis of potential AIG.