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

Monitoring the follow-up of autoimmune chronic atrophic gastritis using parietal cell antibodies and markers of gastric function

Increased interest in the pathogenesis and the evolution of autoimmune chronic atrophic gastritis (A-CAG) has led to the search for serological markers that can be used to detect changes in the gastric mucosa at an early stage and to monitor the course of the disease. Parietal cell autoantibodies have been proposed as suitable immunological markers of atrophic damage, as they can be detected in the serum when symptoms of gastritis are not yet present. However, the utility of measuring only the level of parietal cell autoantibodies in the follow-up of A-CAG does not appear to suffice. Recent evidence has suggested that, in monitoring A-CAG, parietal cell antibodies should be associated with an evaluation of gastric function through biochemical and hormonal tests, such as pepsinogens and gastrin 17. This integrated approach will allow for the more effective real-time monitoring of the state of the gastric mucosa. As A-CAG is a progressive disorder associated with an increased risk of gastric cancer and neuroendocrine tumors, the precise follow-up of patients with gastric atrophy needs to be better defined. Further longitudinal studies in large cohorts must be performed with long-term follow-up.

Olmesartan-associated gastroduodenitis that was detected on endoscopic follow-up

We present a rare case of olmesartan-associated gastroduodenitis in a 65-year-old female with predominant upper gastrointestinal symptoms and significant changes in endoscopic findings over a short period. The patient presented with epigastralgia and nausea but no diarrhea. Esophagogastroduodenoscopy (EGD) performed 26 months earlier showed a duodenal ulcer and partial mucosal atrophy in the lower gastric body. EGD conducted at our hospital revealed diffuse atrophic mucosa throughout the stomach and fragile mucosa from the middle gastric body to the antrum, with white purulent adhesions. Diffuse inflammatory changes were also observed in the duodenal bulb and descending part. Mucosal biopsy showed atrophic changes, inflammatory cell infiltrations, and epithelial detachments in both the stomach and duodenum. Colonoscopy findings were normal. After discontinuing olmesartan, the patient's symptoms improved immediately. A follow-up EGD conducted 4 months after discontinuation revealed marked improvement in the stomach and duodenum. At 16 months post-discontinuation, the patient remained asymptomatic, with minimal inflammation and residual gastric atrophy observed on EGD. This case underscores the importance of considering olmesartan as a potential cause of gastroduodenitis, particularly when symptoms and endoscopic findings improve after discontinuation of the medication.

Gastric cancer in patients with Helicobacter pylori-negative autoimmune gastritis

Although Helicobacter pylori (H. pylori) is implicated in the development of most cases of gastric cancer with autoimmune gastritis, cases of gastric cancer have been reported in patients testing negative for H. pylori. Here, we aimed to outline the current research status of the factors involved in the development of gastric cancer in H. pylori-negative autoimmune gastritis. Predictive pathological conditions for the development of gastric cancer in H. pylori-negative autoimmune gastritis are postulated to be: (1) Severe atrophy; (2) Hypergastrinemia; (3) Bile reflux; and (4) Low acidity, which are directly related to the pathophysiology of autoimmune gastritis, as well as smoking and family history, which are not related to autoimmune gastritis. In autoimmune gastritis, where there is a possibility of spontaneous disappearance of H. pylori in advanced atrophy, it is difficult to assess H. pylori. Since H. pylori infection begins in the antrum and subsequently progresses to the proximal stomach, it is interpreted as H. pylori-negative autoimmune gastritis if histologically consistent with autoimmune gastritis in the body with spared antrum, and negative for other H. pylori tests. However, it is essential to examine whether the currently prevailing histological interpretation used to evaluate H. pylori infection status is appropriate.

A real-world study on the characteristics of autoimmune gastritis: A single-center retrospective cohort in China

BACKGROUND AND AIM

Autoimmune gastritis (AIG) was previously considered a rare disease in China, and its clinical characteristics were not fully understood. This study aimed to demonstrate the characteristics of AIG in China and evaluate gastric oxyntic mucosal atrophy using a modified AIG-atrophic staging.

METHODS

This was a single-center retrospective observational real-world study. The diagnosis of AIG was based on pathological results combined with parietal cell antibody (PCA) and intrinsic factor antibody (IFA) results, and endoscopic findings.

RESULTS

A total of 745 patients were enrolled, the median age at diagnosis was 58 years old, and 69.9 % were female. The symptoms of AIG patients were nonspecific, and about 2/5 of the cases were asymptomatic. The proportions of cases from modified AIG-atrophic stage 1 to 4 were 0.8 %, 14.1 %, 73.8 %, and 11.3 %, respectively. Approximately 1/5 had autoimmune thyroiditis (AITD). Near 1/2 had one or more comorbidities: iron-deficiency anemia (IDA), pernicious anemia (PA), neuropathy, gastric hyperplastic polyps (GHP), gastric intraepithelial neoplasia (GIN), type 1 gastric neuroendocrine tumors (g-NET), or gastric adenocarcinoma (GAC). There was a high risk of type 1 g-NET (7.0 %) and GAC (9.1 %) in AIG patients.

CONCLUSIONS

AIG is not rare in China, and its early diagnosis is challenging, accompanied by a high risk of GAC. The modified four-stage AIG-atrophic staging can effectively represent the extent of oxyntic mucosal atrophy and the progression in AIG.

A novel endoscopic artificial intelligence system to assist in the diagnosis of autoimmune gastritis: a multicenter study

BACKGROUND

 Autoimmune gastritis (AIG), distinct from Helicobacter pylori-associated atrophic gastritis (HpAG), is underdiagnosed due to limited awareness. This multicenter study aimed to develop a novel endoscopic artificial intelligence (AI) system for assisting in AIG diagnosis.

METHODS

 Patients diagnosed with AIG, HpAG, or nonatrophic gastritis (NAG), were retrospectively enrolled from six centers. Endoscopic images with relevant demographic and medical data were collected for development of the AI-assisted system based on a multi-site feature fusion model. The diagnostic performance of the AI model was evaluated in internal and external datasets. Endoscopists' performance with and without AI support was tested and compared using Mann-Whitney U test. Heatmap analysis was performed to interpret AI model outputs.

RESULTS

 18 828 endoscopy images from 1070 patients (294 AIG, 386 HpAG, 390 NAG) were collected. On testing datasets, AI identified AIG with 96.9 % sensitivity, 92.2 % specificity, and area under the receiver operating characteristic curve (AUROC) of 0.990 (internal), and 90.3 % sensitivity, 93.1 % specificity, and AUROC of 0.973 (external). The performance of AI (sensitivity 91.3 %) was comparable to that of experts (87.3 %) and significantly outperformed nonexperts (70.0 %; P = 0.01). With AI support, the overall performance of endoscopists was improved (sensitivity 90.3 % [95 %CI 86.0 %-93.2 %] vs. 78.7 % [95 %CI 73.6 %-83.2 %]; P = 0.008). Heatmap analysis revealed consistent focus of AI on atrophic areas.

CONCLUSIONS

 This novel AI system demonstrated expert-level performance in identifying AIG and enhanced the diagnostic ability of endoscopists. Its application could be useful in guiding biopsy sampling and improving early detection of AIG.

Autoimmune Gastritis in Korean Patients with Gastric Tumors: Clinicopathologic Correlations and Diagnostic Histological Features

Background/Aims

Autoimmune gastritis (AIG) is a corpus-dominant atrophic gastritis in which patients are positive for antiparietal cell antibody (APCA) and/or anti-intrinsic factor antibody. The risk of developing gastric cancer in patients with AIG remains unclear, and reliable frequency data of AIG in patients with gastric cancer are lacking.

Methods

We included 624 Korean patients with gastric tumors (612 gastric cancers and 12 neuroendocrine tumors) who had APCA results and were available for AIG evaluation. In patients with positive APCA results, endoscopy and histology findings were reviewed to diagnose AIG.

Results

Of the 624 patients, 37 (5.9%) tested positive for APCA, and ultimately, 11 (1.8%) met the diagnostic criteria for AIG (5 both endoscopy and histology findings, 4 endoscopy-only findings, 2 histology-only findings). The frequency of AIG in patients with gastric cancer was 1.3% (8/612), and that in patients with neuroendocrine tumors was 25.0% (3/12). Of the 11 patients with AIG, serum Helicobacter pylori antibody was positive in six patients (54.5%), all of whom had gastric cancer. Histologically, three patients showed pure AIG, four patients exhibited concurrent AIG and H. pylori gastritis, and the findings for four were indefinite for AIG. The pepsinogen (PG) I levels and PG I/II ratio were significantly lower in patients with gastric cancer with AIG than in patients with gastric cancer without AIG (p=0.042 and p=0.016, respectively).

Conclusions

The frequency of AIG in gastric cancer patients was very low compared to that in patients with neuroendocrine tumors. Rather, concurrent AIG and H. pylori gastritis was common in patients with AIG with gastric cancer.

Autoimmune Gastritis Complicated by Primary Biliary Cholangitis: A Report of Two Cases and Literature Review

Although autoimmune gastritis (AIG) is often associated with various autoimmune diseases, including type 1 diabetes and Hashimoto's thyroiditis, it is rarely associated with primary biliary cholangitis (PBC). Herein, we present two cases in which AIG was found to be a complication during follow-up of PBC, both histologically diagnosed as AIG with positive autoantibodies and also serologically typical for AIG, including pepsinogen and gastrin. In the first case, a 60-year-old woman with PBC was suspected of having AIG based on endoscopic findings. A definitive diagnosis of AIG was established based on a positive anti-parietal cell antibody test and characteristic histologic findings. The patient exhibited a low pepsinogen I level (5.5 pg/mL; normal: >70 pg/mL) and hypergastrinemia (637 pg/mL; normal: 37-172 pg/mL). Additionally, she was diagnosed with Hashimoto's thyroiditis, confirmed by the presence of anti-thyroid antibodies and an enlarged thyroid gland. In the second case, a 70-year-old woman with PBC was suspected of having AIG due to the low pepsinogen I level (5.8 pg/mL). The definitive diagnosis was established based on the presence of positive anti-intrinsic factor antibodies and characteristic histologic findings. The patient also exhibited hypergastrinemia (2845 pg/mL), but no additional autoimmune diseases were observed. In reviewing past case reports, we identified seven previous reports of AIG with PBC other than our two cases. Approximately half (4/9) were macrocytic anemia, and approximately half (4/9) were positive for anti-thyroid antibodies, which is higher than that expected for conventional PBC. Because AIG should not be misdiagnosed because of the high frequency of associated malignancies, other concomitant autoimmune diseases, and vitamin B12 deficiency, it should be considered in the surveillance of PBC, especially in those with macrocytic anemia or positive antithyroid antibodies.

A Case of Synchronous and Metachronous Gastric Neoplasms Associated With Autoimmune Gastritis

Patients with autoimmune gastritis (AIG) are reported to be associated with an increased risk of developing gastric neuroendocrine and gastric tumors. Again, those with cancer are shown to be at risk of developing multiple primary cancers within two months of the first primary cancer (synchronous cancers) or more than two months afterward (metachronous cancers). A 78-year-old man was diagnosed with early gastric cancer and referred to our hospital for endoscopic treatment. Curative resection was performed with endoscopic submucosal dissection (ESD), which also revealed AIG in the background gastric mucosa. Follow-up esophagogastroduodenoscopy (EGD) performed three months later revealed an erythematous, superficial depressed lesion and a whitish, superficial flat lesion in the greater curvature of the gastric angle, which established the diagnosis of early gastric cancers. Curative resection was again performed with ESD. Retrospectively, one of these lesions was found to be a synchronous gastric cancer. A follow-up EGD performed one year later newly detected a 5 mm adenoma in the gastric angle, which was treated endoscopically as a metachronous lesion. Thus, the present case highlights the need to watch for multiple primary cancers when treating patients with cancer, particularly those with AIG.

Autoimmune diseases and risk of gastrointestinal cancer: an umbrella review of meta-analyses of observational studies

BACKGROUND

Several autoimmune diseases (ADs) are considered risk factors for gastrointestinal (GI) cancers. This study pooled and appraised the evidence associating ADs with GI cancer risks.

METHODS

Three databases were examined from initiation through 26 January 2024. Evidence was determined by the criteria including the P -value of random-effects, small-study effects, excess significance bias, heterogeneity, and 95% prediction interval.

RESULTS

Fourteen meta-analyses including 211 primary studies describing 31 associations were selected. Inflammatory bowel disease (IBD) and Crohn's disease (CD) are strong risk factors (with effect sizes of 10.33 and 12.12, respectively) for small bowel cancer (SBC), as indicated by highly suggestive evidence. Another highly suggestive evidence is that gastric cancer (GC) risk was elevated in individuals suffering from pernicious anemia (PA, effect size: 2.80). Suggestive evidence emerged that the risks of colorectal cancer (CRC) were decreased in patients with rheumatoid arthritis (RA, effect size: 0.79) but increased in patients with IBD (effect size: 1.82).

CONCLUSIONS

This study finds three highly suggestive pieces of evidence of IBD and CD patients with higher SBC risk and PA patients with higher GC risk. Future studies should identify these associations to provide more personalized cancer screenings for patients with ADs.

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.

Endoscopic and clinical characteristics of autoimmune atrophic gastritis: Retrospective study

Background and study aims

Autoimmune atrophic gastritis (AIG) is a rare chronic autoimmune disease characterized by gastric mucosa inflammation and atrophy. Limited clinical data exist about AIG, especially in western populations. In addition, there are no western series on the magnifying endoscopic features in AIG. This study presents a cohort of 63 patients with AIG, reporting their clinical, laboratory, and endoscopic findings.

Patients and methods

A retrospective analysis was conducted on patients diagnosed with AIG at Kingston Health Sciences Centre, Canada, between January 2016 and December 2023. Data collected from medical records included age, sex, presenting symptoms, laboratory findings, endoscopic features, histopathology reports, and concomitant autoimmune diseases.

Results

The study included 63 patients with autoimmune gastritis. Positive anti-parietal cell antibodies were found in the majority of patients (84.13%), whereas positive anti-intrinsic factor antibodies were less prevalent (25.40%). Deficiencies in vitamin B12 (49.21%) and iron (76.19%) were observed, along with a high prevalence of anemia (71.43%) and concomitant autoimmune diseases (58.73%). The dominant magnification pattern of atrophy in the body was oval/slit in 57.14% of patients (n=36), followed by tubular in 30.16% (n=19) and foveolar in 12.70% (n=8). Prevalence of neoplasia in our study was 42.86% (n=27).

Conclusion

This study offers insights into the clinical, laboratory, and magnifying endoscopic features of patients with AIG. It demonstrates the three main magnifying endoscopic appearances of AIG and highlights the significant prevalence of gastric neoplasia, even in the low-risk Western population. These findings emphasize the importance of the endoscopic exam in identifying AIG and notably present the key magnifying endoscopy findings in a Western setting for the first time.

Arising of autoimmune gastritis after helicobacter pylori eradication in an elderly female patient

Autoimmune gastritis (AIG) is a chronic condition in which the body's immune system mistakenly attacks the stomach lining, specifically targeting parietal cells that produce stomach acid and intrinsic factors. After the H. pylori infection was eradicated, AIG developed in an elderly woman with symptoms of the disease. 1.5 years after eradication, esophagogastroduodenoscopy revealed remnants of the oxyntic mucosa sticky adherent dense mucus and scattered minute whitish protrusions at the greater curvature of the gastric corpus. Biopsy specimens from the greater curvature site of the gastric corpus before H. pylori eradication revealed neutrophilic cells in the superficial mucosa of the stomach that were mildly inflammatory and infiltrating. With the removal of H. pylori, the number of infiltrating inflammatory neutrophilic cells in the superficial mucosa decreased, whereas that of infiltrating lymphocytes increased in the sub-superficial mucosa. This case suggests that further studies regarding the detailed time course of AIG are required.

Synchronous cancers of the stomach and esophagus in a patient with autoimmune gastritis and pernicious anemia: a case report and review of the literature

Type-A gastritis/autoimmune gastritis (AIG) has gained renewed attention due to declining Helicobacter pylori infection rates and increasing eradication. AIG is associated with pernicious anemia (PA) and is prone to complicate various tumors, such as gastric cancer and neuroendocrine tumors. This report describes a case of AIG with PA in which gastric and esophageal cancers arose simultaneously. An 86-year-old woman had been diagnosed with PA and AIG 9 years earlier. As routine blood tests revealed high levels of carcinoembryonic antigen, she underwent esophagogastroduodenoscopy, which revealed a type 0-IIa lesion in the middle part of the stomach and a type 0-IIa + IIb lesion in the lower esophagus. Endoscopic submucosal dissection was performed on both lesions, since neither distant nor lymph node metastases were identified. Histological examination showed gastric tubular adenocarcinoma and esophageal squamous cell carcinoma. Immunohistology revealed that cells from neither cancer expressed gastrin, gastrin receptor, or p53. Whole-exome sequencing showed 8 gene mutations in the esophageal cancer and 6 mutations in 5 genes in the gastric cancer. The reason for the lack of p53 immunostaining was that TP53 was mutated in these cancers, although TP53 mutations differed. Thus, TP53 mutations may not be detected by immunostaining alone. When treating patients with AIG/PA, clinicians must be aware of the possibility of esophageal cancer coexisting with gastric cancer.

H. pylori-Associated Gastritis, Gastritis after H. pylori Eradication and H. pylori-Negative Gastritis: Algorithm of Diagnosis and Treatment (Literature Review and Resolution of the Expert Panel of the Russian Gastroenterological Association)

Aim: to provide the basic points of the Expert Panel of the Russian Gastroenterological Association with discussion of measures to improve diagnostics, treatment and management of chronic gastritis patients.

Key points. In the Russian Federation in 2021 more than 30 million patients diagnosed with “Gastritis and duodenitis” were recorded (K29 in accordance with International Classification of Diseases-10). H. pylori incidence rate in the Russian population has reduced and presently is about 40 %. In chronic gastritis pattern H. pylori-associated gastritis has still dominated though gastritis percent after successful H. pylori eradication, reactive gastropathy (including reflux gastritis) and autoimmune gastritis, has increased. Endoscopic and histologic examinations serve as key diagnostic techniques that provide a means for assessing the ethiology of gastritis, topography and degree of atrophic changes, gastritis staging as per OLGA/OLGIM system that properly correlates with the risk of stomach cancer and determines endoscopic examination strategy. H. pylori eradication therapy of gastritis serves as an etiotropic treatment and makes it possible to prevent progression of atrophy and stomach cancer. Conventional triple therapy combined with bismuth tripotassium dicitrate allows for achieving optimal cure rates of H. pylori eradication. Addition of rebamipide to regimens of H. pylori eradication improves their efficiency. Rebamipide arrests symptoms of dyspepsia in the case of chronic gastritis and functional dyspepsia. The administration of rebamipide for chronic gastritis makes it possible to influence the syndrome of increased epithelial permeability and inflammation, which makes it advisable to study it as a means of preventing stomach cancer and the progression of atrophy in various types of chronic gastritis.

Conclusion. Members of the Expert Panel has approved the algorithm of diagnosis and treatment of H. pylori-associated gastritis, gastritis after H. pylori eradication and H. pylori-negative gastritis at the diagnostic stage in the case of initial presentation and long-term follow-up when needed.

Multiple gastric neuroendocrine tumors in a patient with parietal cell dysfunction and adenosine triphosphatase H+/K+ transporting subunit alpha gene variant

A 47-year-old woman presented with multiple gastric tumors, each up to 10 mm in diameter, in the gastric body and fundus without mucosal atrophy. White spots and numerous transparent, light-brownish, small, and rounded spots were observed in the background gastric mucosa. Biopsy specimens obtained from the tumors revealed gastric neuroendocrine tumors. The patient exhibited hypergastrinemia and achlorhydria and tested negative for serum parietal cell antibody, intrinsic factor antibody, and Helicobacter pylori infection. Moreover, no additional lesions were detected on imaging. These findings were inconsistent with Rindi's classification. The tumor was resected via endoscopic submucosal resection. Histopathological examination revealed gastric neuroendocrine tumors G2 infiltrating the submucosa with no atrophy of the gastric mucosa, dilated fundic glands, parietal cell protrusions, and hyperplasia of enterochromaffin-like cells. Immunohistochemically, the parietal cells were negative for both α- and β-subunits of H+/K+ ATPase, suggesting parietal cell dysfunction. A genomic variant was identified in adenosine triphosphatase H+/K+ transporting subunit alpha. After 7 years of treatment, there was no evidence of residual or metastatic lesions. Modification of adenosine triphosphatase H+/K+ transporting subunit alpha may be a significant factor in the pathogenesis of multiple gastric neuroendocrine tumors in the context of gastric parietal cell dysfunction.

Characteristic endoscopic findings in Helicobacter pylori diagnosis in clinical practice

INTRODUCTION

Helicobacter pylori is a major risk factor for gastric cancer. In addition to eradication therapy, early-phase detection of gastric cancer through screening programs using high-vision endoscopy is also widely known to reduce mortality. Although European and US guidelines recommend evaluation of atrophy and intestinal metaplasia by high-vision endoscopy and pathological findings, the guideline used in Japan - the Kyoto classification of gastritis - is based on endoscopic evaluation, and recommends the grading of risk factors. This system requires classification into three endoscopic groups: H. pylori-negative, previous H. pylori infection (inactive gastritis), and current H. pylori infection (active gastritis). Major endoscopic findings in active gastritis are diffuse redness, enlarged folds, nodularity, mucosal swelling, and sticky mucus, while those in H pylori-related gastritis - irrespective of active or inactive status - are atrophy, intestinal metaplasia, and xanthoma.

AREAS COVERED

This review describes the endoscopic characteristics of current H. pylori infection, and how characteristic endoscopic findings should be evaluated.

EXPERT OPINION

Although the correct evaluation of endoscopic findings related to H. pylori remains necessary, if findings of possible infection are observed, it is important to diagnose infection by detection methods with high sensitivity and specificity, including the stool antigen test and urea breath test.

A Novel Characteristic Gastric Mucus Named "Web-like Mucus" Potentially Induced by Vonoprazan

Background: In the absence of Helicobacter pylori (HP) infection, a characteristic gastric mucus adhesion may appear during the use of vonoprazan. We named this novel characteristic mucus "web-like mucus" (WLM). This study aimed to determine the incidence and risk factors for WLM. Methods: Between January 2017 and January 2022, 5665 patients were enrolled in this study. The patients were divided into a proton-pump inhibitor (PPI)-prescribed group (n = 2000), a vonoprazan-prescribed group (n = 268), and a no-PPI/vonoprazan-prescribed (n = 3397) group, and the presence of WLM was examined. After excluding four patients with autoimmune gastritis, the remaining 264 patients in the vonoprazan group were divided into WLM and non-WLM groups, and their clinical features were analyzed. Results: A total of 55 (21%) patients had WLM, all in the vonoprazan-prescribed group. There were no significant differences in factors such as, sex, age, chronic kidney disease, diabetes mellitus, HP eradication history, smoking, or alcohol consumption between the WLM and non-WLM groups. The median duration from the start of vonoprazan administration to the endoscopic detection of WLM was 2 (1-24) months. Conclusions: WLM appears to be a characteristic feature in patients treated with vonoprazan.

Endoscopic Grading and Sampling of Gastric Precancerous Lesions: A Comprehensive Literature Review

Gastric cancer remains a disease with an ominous prognosis, while early gastric cancer has a good-to-excellent prognosis, with 5-year survival rates of up to 92.6% after successful endoscopic resection. In this context, the accurate identification of patients with established gastric precancerous lesions, namely chronic atrophic gastritis and intestinal metaplasia, is the first step in a stepwise approach to minimize cancer risk. Although current guidelines advocate for the execution of random biopsies to stage the extent and severity of gastritis/intestinal metaplasia, modern biopsy protocols are still imperfect as they have limited reproducibility and are susceptible to sampling error. The advent of novel imaging-enhancing modalities, i.e., high-definition with virtual chromoendoscopy (CE), has revolutionized the inspection of gastric mucosa, leading to an endoscopy-based staging strategy for the management of these premalignant changes in the stomach. Nowadays, the incorporation of CE-targeted biopsies in everyday clinical practice offers not only the robust detection of premalignant lesions but also an improvement in quality, by reducing missed diagnoses along with mean biopsies and, thus, the procedural costs and the environmental footprint. In this review, we summarize the recent evidence regarding the endoscopic grading and sampling of gastric precancerous lesions.

Unveiling early stage autoimmune gastritis: novel endoscopic insights from two case reports

The predominant characteristic of autoimmune gastritis (AIG) is corpus-dominant advanced atrophy, which is mostly observed in the middle to late stages. More reports are needed on the endoscopic features of the early stage. In this report, we present two cases of early-stage AIG in which endoscopic examinations showed no atrophy of the gastric mucosa but displayed a transition of collecting venules from a regular to an irregular arrangement. In addition, yellowish-white cobblestone-like elevations were observed in the fundic gland region. Histologically, the observed manifestations included pseudohypertrophy and protrusion of parietal cells into the lumen, possibly along with hyperplasia of G cells, lymphocytic infiltration and potentially pseudopyloric gland metaplasia. Serologically, the anti-parietal cell antibody returned positive results, whereas the anti-intrinsic factor antibody yielded negative results. In this study, we summarized some endoscopic features of two patients, aiming to provide clues for endoscopists to detect early-stage AIG.

Clinicopathological Features of Early Gastric Cancer Complicated by Autoimmune Gastritis

INTRODUCTION

In the post-Helicobacter pylori era, autoimmune gastritis (AIG) is attracting increasing attention as an origin of gastric cancer. Here, we performed clinicopathological examination of gastric cancer complicating AIG treated in our hospital.

METHODS

Eighty-six early gastric cancer lesions complicating AIG in 50 patients were treated by endoscopic submucosal dissection (ESD) at our hospital in 2008-2022. Their clinicopathological characteristics were compared with those of a control group comprising 2,978 early gastric cancer lesions (excluding lesions in the remnant stomach after surgery) in 2,278 patients treated by ESD during the same period.

RESULTS

Mean age was significantly higher in the AIG group than in the control group (74.7 years vs. 70.9 years; p < 0.01). In the respective groups, the occurrence rate of synchronous/metachronous lesions was 38.0% and 20.4% (p < 0.01), the ratio of longitudinal cancer locations (upper/middle/lower third [U/M/L]) was 27/32/27 and 518/993/1,467 (p < 0.01), the ratio of circumferential cancer locations (lesser curvature/greater curvature/anterior wall/posterior wall) was 25/31/12/18 and 1,259/587/475/657 (p < 0.01), the ratio of major macroscopic types (I/IIa/IIb/IIc) was 13/38/5/30 and 65/881/220/1,812 (p < 0.01). The rates of multiple gastric cancer and cancers in the U region, at the greater curvature, and of protruding types were significantly higher in the AIG group.

CONCLUSION

The occurrence rate of multiple gastric cancer was significantly higher in gastric cancer complicating AIG (approximately 40%), and compared with the control group, the proportions of cancers at the U region, at the greater curvature, and of protruding types were significantly higher.

A case of nodular gastritis progression to autoimmune gastritis after 10 years of Helicobacter pylori eradication

A 61-year-old female patient underwent upper gastrointestinal endoscopy, which confirmed the presence of Helicobacter pylori (H. pylori)-positive nodular gastritis (NG). Routine upper gastrointestinal endoscopy after H. pylori eradication revealed atrophic changes of the corpus, having gradually progressed over the 10 years after successful eradication. Serological and biopsy specimen examination showed hypergastrinemia (1200 pg/mL), positive anti-parietal cell antibody (with a titer of more 160), and endocrine cell micronests after 11 years of H. pylori eradication. The patient was diagnosed with autoimmune gastritis (AIG) based on endoscopic, serological, and histological findings. This is the first report of AIG diagnosed in a patient with NG over a long period of time after H. pylori eradication.

Autoimmune Atrophic Gastritis: A Clinical Review

Autoimmune atrophic gastritis (AAG) is a chronic condition characterized by the presence of atrophy in the oxyntic mucosa due to anti-parietal cell antibodies. This review provides a comprehensive and up-to-date overview of autoimmune atrophic gastritis, reporting recent evidence on epidemiology, pathogenesis, diagnosis, clinical presentation, risk of malignancies, and management. The prevalence of AAG has been estimated at between 0.3% and 2.7% in the general population. The diagnosis of AAG is based on a combination of the serologic profile and the histological examination of gastric biopsies. Patients with AAG are often asymptomatic but can also have dyspeptic or reflux symptoms. The atrophy of the oxyntic mucosa leads to iron and vitamin B12 malabsorption, which may result in anemia and neurological affections. Autoimmune atrophic gastritis is associated with an increased risk of type I neuroendocrine tumors (NETs) and gastric cancer, with an incidence rate of 2.8% and 0.5% per person/year, respectively. Management is directed to reinstate vitamins and iron and to prevent malignancies with endoscopic surveillance. In conclusion, atrophic autoimmune gastritis is an infrequent condition, often asymptomatic and misdiagnosed, that requires an early diagnosis for appropriate vitamin supplementation and endoscopic follow-up for the early diagnosis of NETs and gastric cancer.

Characteristic endoscopic findings in early-stage autoimmune gastritis

Background and study aims Until recently, autoimmune gastritis (AIG) was usually diagnosed at late stages based on typical endoscopic findings, including corpus-dominant advanced atrophy. Early-stage AIG prior to complete gastric atrophy had rarely been diagnosed due to a lack of knowledge about its endoscopic characteristics. The present study sought to identify the endoscopic characteristics of early-stage AIG, enabling its early diagnosis. Patients and methods The clinical and endoscopic findings of 12 patients diagnosed with early-stage AIG between 2016 and 2021 were retrospectively evaluated. Patients were included if they were: (1) positive for serum anti-parietal cell antibody; (2) diagnosed with histological early-stage AIG; and (3) endoscopically positive for folds on the greater curvature of the gastric corpus. Results Two characteristic endoscopic findings of early-stage AIG were identified: longitudinal alignment of pseudopolyps (i.e., a bamboo joint-like appearance) and swelling of gastric areas with erythema (i.e., a salmon roe-like appearance). Conclusions Endoscopic findings characteristic of early-stage AIG include a bamboo joint-like appearance and a salmon roe-like appearance. Studies in large numbers of patients with long-term follow-up are needed to confirm these findings.

RE.GA.IN.: the Real-world Gastritis Initiative-updating the updates

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.

Autoimmune Gastritis: Focus on Endoscopic and Morphological Characteristics

Aim: tosystematize the literature data on endoscopic semiotics and morphological changes in the gastric mucosa in autoimmune gastritis.

Key points. Autoimmune gastritis is associated with an increased risk of developing adenocarcinoma and neuroendocrine tumours of the stomach. Clarification of diagnostic criteria for autoimmune gastritis is essential for gastroenterological practice. The diagnosis is based on the results of endoscopic and histological examination, and on data from laboratory tests. Isolated atrophy of the mucous membrane of the body of the stomach, the presence of difficult-to-wash creamy mucus, changes in the mucous membrane like “shed skin”, and the presence of whitish globule-like foci are typical endoscopic signs of autoimmune gastritis. Widespread pseudopyloric metaplasia, focal intestinal and pseudopancreatic metaplasia, hyperplasia of the ridges of the mucous membrane of the body of the stomach and their relationship to the glandular layer as in the antrum allow during a morphological study considering clinical data to suspect and verify autoimmune gastritis.

Conclusion. During instrumental examination, knowledge of endoscopic symptoms and pathognomonic morphological changes is important for the timely diagnosis of autoimmune gastritis.

Clinical experience sharing on gastric microneuroendocrine tumors: A case report

BACKGROUND

The majority of gastric neuroendocrine tumors (G-NENs) are present in various lesions under endoscopy, and they can be polypoid uplifts, submucosal tumors or papules, erosions, and ulcers. The lesions are mostly confined to the mucosal or submucosal layer, usually less than 2 cm, and exclusively localized to the gastric body or fundus. In type 1 G-NENs, about 22% of cases have no visible lesions under an endoscope, and such lesions can only be detected via biopsies (microcarcinoids).

CASE SUMMARY

A 67-year-old female patient with appetite loss for more than half a year and personal history of hyperthyroidism was admitted to our hospital. After admission, a random multi-point biopsy was performed on the gastric body, fundus, angle, and antrum through gastroscopy. Pathological examination showed chronic severe atrophic gastritis in the fundus and body of the stomach. The small curvature of the gastric body, the anterior wall of the gastric body, and the posterior wall of the gastric body displayed proliferation of intestinal chromaffin cells. The curvature of the gastric body showed neuroendocrine tumor G1 (carcinoid), while the antrum and angle of the stomach showed mild atrophic gastritis with mild intestinal metaplasia. Immunohistochemical examination showed that the greater curvature of the gastric body was Syn (+), CgA (+), and Ki-67 (+, approximately 1%), which is consistent with neuroendocrine tumors (grade 1). Regular gastroscopy and biopsy should be performed every one to two years to monitor G-NENs.

CONCLUSION

In the case under study, the patient did not have any visible raised lesions under a gastroscope, and the lesions were found only after a random biopsy. This article combines the endoscopic manifestations and clinical features of the lesions in this case to improve the diagnosis of G-NENs.

Marked intestinal trans-differentiation by autoimmune gastritis along with ectopic pancreatic and pulmonary trans-differentiation

BACKGROUND

Autoimmune gastritis (AIG) is a prevalent chronic inflammatory disease with oncogenic potential that causes destruction of parietal cells and severe mucosal atrophy. We aimed to explore the distinctive gene expression profiles, activated signaling pathways, and their underlying mechanisms.

METHODS

A comprehensive gene expression analysis was conducted using biopsy specimens from AIG, Helicobacter pylori-associated gastritis (HPG), and non-inflammatory normal stomachs. Gastric cancer cell lines were cultured under acidic (pH 6.5) conditions to evaluate changes in gene expression.

RESULTS

Gastric mucosa with AIG had a unique gene expression profile compared with that with HPG and normal mucosa, such as extensively low expression of ATP4A and high expression of GAST and PAPPA2, which are involved in neuroendocrine tumorigenesis. Additionally, the mucosa with AIG and HPG showed the downregulation of stomach-specific genes and upregulation of small intestine-specific genes; however, intestinal trans-differentiation was much more prominent in AIG samples, likely in a CDX-dependent manner. Furthermore, AIG induced ectopic expression of pancreatic digestion-related genes, PNLIP, CEL, CTRB1, and CTRC; and a master regulator gene of the lung, NKX2-1/TTF1 with alveolar fluid secretion-related genes, SFTPB and SFTPC. Mechanistically, acidic conditions led to the downregulation of master regulator and stemness control genes of small intestine, suggesting that increased environmental pH may cause abnormal intestinal differentiation in the stomach.

CONCLUSIONS

AIG induces diverse trans-differentiation in the gastric mucosa, characterized by the transactivation of genes specific to the small intestine, pancreas, and lung. Increased environmental pH owing to AIG may cause abnormal differentiation of the gastric mucosa.

Critical influence of cytokines and immune cells in autoimmune gastritis

Gastric cancer (GC) is a type of the most common cancers. Autoimmune gastritis (AIG) and infection with Helicobacter pylori (HP) are the risk factors of triggering GC. With the emphasis on the treatment of HP, the incidence and prevalence of HP infection in population is decreasing. However, AIG lacks accurate diagnosis and treatment methods, which occupies high cancer risk factors. AIG is controlled by the immune environment of the stomach, including immune cells, inflammatory cells, and infiltrating intercellular material. Various immune cells or cytokines play a central role in the process of regulating gastric parietal cells. Abnormal expression levels of cytokines involved in immunity are bound to face the risk of tumorigenesis. Therefore, it is particularly important for preventing or treating AIG and avoiding the risk of gastric cancer to clarify the confirmed action mode of immune cells and cytokines in the gastric system. Herein, we briefly reviewed the role of the immune environment under AIG, focussing on describing these double-edged effects between immune cells and cytokines, and pointing out potential research challenges.

Research status and hotspots of autoimmune gastritis: A bibliometric analysis

BACKGROUND

As an emerging potential risk factor for gastric cancer, autoimmune gastritis (AIG) has garnered increasing attention from researchers.

AIM

To analyze the research overview and popular topics in the field of AIG using bibliometrics.

METHODS

Relevant publications on AIG in the Web of Science Core Collection were collated, and data visualization and analysis of the number of publications, countries, institutions, journals, authors, keywords, and citations were performed using software such as VOSviewer, CiteSpace, and Scimago Graphic.

RESULTS

In total, 316 relevant articles were included in the analysis. From 2015 to 2022, the number of publications increased annually. The countries, institutions, authors, and journals with the highest number of publications in this field were Italy, Monash University, Toh BH, and Internal Medicine. The main keywords used in this field of research were pathogenesis, Helicobacter pylori, autoantibody, parietal cell antibody, atrophic gastritis, classification, diagnosis, autoimmune disease, risk, cancer, gastric cancer, vitamin B12 deficiency, and pernicious anemia. The following directions may be popular for future research: (1) The role of Helicobacter pylori in the pathogenesis of AIG; (2) diagnostic criteria for AIG and reference values for serum antibodies; (3) comorbidity mechanisms between AIG and other autoimmune diseases; (4) specific risks of AIG complicating gastric and other cancers; and (5) the role of vitamin B12 supplementation in patients with early-stage AIG.

CONCLUSION

This bibliometric analysis reported on popular topics and emerging trends in AIG, with diagnosis and prognosis being research hotspots in this field.

Increased Prevalence of Autoimmune Gastritis in Patients with a Gastric Precancerous Lesion

Background: Autoimmune gastritis (AIG), characterized with the presence of anti-parietal-cell antibodies (APCA), is a risk factor for gastric cancer. However, AIG may go underdiagnosed, especially in the case of H. pylori infection and the presence of gastric precancerous lesions (GPL), due to the ambiguous pathology and delayed symptom onset. Aim: Investigate the prevalence and characteristics of AIG in GPL patients. Methods: Prevalence of AIG was determined with the presence of APCA in patients with GPL (n = 256) and the control group (n = 70). Pathological characteristics and levels of gastrin 17 (G17), pepsinogen (PG) I and II and anti-Helicobacter pylori IgG were assessed in GPL cases, and the severity of intestinal metaplasia and gastric atrophy was scored by expert pathologists. Results: APCA positivity was observed in 18% of cases vs. 7% of controls (p = 0.033). Only 3/256 patients were previously diagnosed with AIG. The presence of APCA was associated with corpus-limited and extended GPL. A receiver operating curve analysis demonstrated that the G17 and PGI/II ratio could identify APCA-positive patients within GPL cases (AUC: 0.884). Conclusions: The prevalence of AIG is higher in patients with GPL but goes undiagnosed. Using G17 and PG I/II as diagnostic markers can help to identify patients with AIG and improve surveillance programs for patients with GPL.

Clinical characteristics and long-term prognosis of type 1 gastric neuroendocrine tumors in a large Japanese national cohort

OBJECTIVES

Optimal management of type 1 gastric neuroendocrine tumors (T1-GNETs) remains unknown, with few reports on their long-term prognosis. This study investigated the clinical characteristics and long-term prognosis of T1-GNETs.

METHODS

We reviewed the medical records of patients diagnosed with T1-GNET during 1991-2019 at 40 institutions in Japan.

RESULTS

Among 172 patients, endoscopic resection (ER), endoscopic surveillance, and surgery were performed in 84, 61, and 27, respectively, including 27, 77, and 2 patients with pT1a-M, pT1b-SM, and pT2 tumors, respectively. The median tumor diameter was 5 (range 0.8-55) mm. Four (2.9%) patients had lymph node metastasis (LNM); none had liver metastasis. LNM rates were significantly higher in tumors with lymphovascular invasion (LVI) (15.8%; 3/19) than in those without (1.1%; 1/92) (P = 0.016). For tumors <10 mm, LVI and LNM rates were 18.4% (14/76) and 2.2% (2/90), respectively, which were not significantly different from those of tumors 10-20 mm (LVI 13.3%; 2/15, P = 0.211; and LNM 0%; 0/17, P = 1.0). However, these rates were significantly lower than those of tumors >20 mm (LVI 60%; 3/5, P = 0.021; and LNM 40%; 2/5, P = 0.039). No tumor recurrence or cause-specific death occurred during the median follow-up of 10.1 (1-25) years. The 10-year overall survival rate was 97%.

CONCLUSIONS

Type 1 gastric neuroendocrine tumors showed indolent nature and favorable long-term prognoses. LVI could be useful in indicating the need for additional treatments. ER for risk prediction of LNM should be considered for tumors <10 mm and may be feasible for tumors 10-20 mm.

TRIAL REGISTRATION

The study protocol was registered in the University Hospital Medical Information Network (UMIN) under the identifier UMIN000029927.

Gastric neuroendocrine tumors in a BRCA2 germline mutation carrier: A case report

BACKGROUND

The molecular changes present in gastric neuroendocrine tumors (NETs) include a loss of heterozygosity or mutation of MEN1, CDKN1B gene mutation, P27 heterozygous mutation, and ATP4A gene missense mutation. We identified and are the first to report a case of type 1 histamine-producing enterochromaffin-like cell NETs (ECL-cell NETs) with a BRCA2 gene germline mutation.

CASE SUMMARY

The patient had a history of iron-deficient anemia for 5 years, and gastroscopic examination indicated multiple gastric tumors. Then, the patient underwent distal gastrectomy. Microscopically, multifocal tumor cells were found in the mucosa and submucosa; tumor cells were organoid and arranged in nests and cords, and the stroma was rich in sinusoids. The surrounding gastric mucosa showed atrophy with mild intestinal metaplasia or pseudopyloric gland metaplasia. Neuroendocrine cells could be seen with diffuse linear, nodular, and adenomatous hyperplasia. Immunohistochemically, the tumor cells diffusely expressed cytokeratin, chromogranin, synaptophysin, and CD56. Whole-genome high-throughput molecular sequencing revealed a pathogenic germline mutation in the BRCA2 gene, a heterozygous germline frameshift mutation in exon 11, c.6443_6444del (p.S2148Yfs*2). The final diagnosis was gastric type 1 ECL-cell NETs with a BRCA2 gene germline mutation, accompanied by autoimmune gastritis.

CONCLUSION

This is the first report of a case of type 1 gastric ECL-cell NETs with a pathogenic germline mutation of the BRCA2 gene. The findings of this report will expand the germline mutation spectrum of gastric NETs and increase the understanding of the molecular changes present in these tumors for their improved diagnosis in the future.

Clinicopathological characteristics of autoimmune gastritis: A single-center retrospective study

BACKGROUND AND AIM

Autoimmune gastritis (AIG) is a prominent risk factor for pernicious anemia (PA) and gastric neoplasia. This study aimed to investigate the clinicopathological characteristics of AIG patients in China, with a focus on those who had positive anti-intrinsic factor antibodies (AIFA).

METHODS

A total of 103 AIG patients who were diagnosed between January 2018 and August 2022 were reviewed in a large academic tertiary teaching hospital. Patients were divided into two groups based on the presence or absence of AIFA, and their serologic and histopathological characteristics were analyzed.

RESULTS

The mean age of the 103 AIG patients was 54.16±11.92 years (range 23-79), with 69 (66.99%) being women. AIFA were present in 28.16% of patients. Patients with AIFA-positive had a higher risk of PA than those with AIFA-negative, as demonstrated by a larger mean corpuscular volume (MCV), lower hemoglobin level, and lower vitamin B-12 level (P<0.05). There were no statistically significant differences in gastric histopathology, gastrin level, and pepsinogen level when patients were divided into AIFA-positive and AIFA-negative group. Of the 103 cases, 34 (33.01%) were concomitant with other autoimmune diseases, with autoimmune thyroid diseases being the most common (25.24%, 26/103). Thyroid peroxidase antibody, which accounted for 45.45% (25/55), was the most prevalent thyroid antibody, followed by anti-thyroglobulin antibody (34.55%, 19/55), thyroid stimulating antibody (12.73%, 7/55), and thyrotropin receptor antibody (3.64%, 2/55).

CONCLUSION

This study highlights the increased risk of severe anemia in AIFA-positive AIG patients, particularly for PA. Clinicians should consider the presence of AIFA as a warning sign for PA and prioritize early diagnosis and appropriate treatment to prevent serious complications.

Update in Molecular Aspects and Diagnosis of Autoimmune Gastritis

Recent studies have advanced our understanding of the pathophysiology of autoimmune gastritis, particularly its molecular aspects. The most noteworthy recent advancement lies in the identification of several candidate genes implicated in the pathogenesis of pernicious anemia through genome-wide association studies. These genes include PTPN22, PNPT1, HLA-DQB1, and IL2RA. Recent studies have also directed attention towards other genes such as ATP4A, ATP4B, AIRE, SLC26A7, SLC26A9, and BACH2 polymorphism. In-depth investigations have been conducted on lymphocytes and cytokines, including T helper 17 cells, interleukin (IL)-17A, IL-17E, IL-17F, IL-21, IL-19, tumor necrosis factor-α, IL-15, transforming growth factor-β1, IL-13, and diminished levels of IL-27. Animal studies have explored the involvement of roseolovirus and H. pylori in relation to the onset of the disease and the process of carcinogenesis, respectively. Recent studies have comprehensively examined the involvement of autoantibodies, serum pepsinogen, and esophagogastroduodenoscopy in the diagnosis of autoimmune gastritis. The current focus lies on individuals demonstrating atypical presentations of the disease, including those diagnosed in childhood, those yielding negative results for autoantibodies, and those lacking the typical endoscopic characteristics of mucosal atrophy. Here, we discuss the recent developments in this field, focusing on genetic predisposition, epigenetic modifications, lymphocytes, cytokines, oxidative stress, infectious agents, proteins, microRNAs, autoantibodies, serum pepsinogen, gastrin, esophagogastroduodenoscopy and microscopic findings, and the risk of gastric neoplasm.

Rapid Progression of Autoimmune Gastritis after Helicobacter pylori Eradication Therapy

We herein report a case of autoimmune gastritis (AIG) with rapid progression after Helicobacter pylori eradication therapy. The patient's previous gastritis had followed the course of type B gastritis before eradication therapy for many years. Immediately after eradication, we diagnosed her with AIG and carefully followed changes in the endoscopic and histopathological findings and serum markers. All of these clinical findings showed significant atrophic progression in the corporal area for approximately three years. We concluded that H. pylori eradication therapy exacerbated AIG in this case.

Histopathologic diagnosis of ultra-early autoimmune gastritis: A case report

We describe an ultra-early stage of autoimmune gastritis (AIG) that occurs prior to the well-known early-stage AIG. The key pathology is the shortening of the second layer with degenerated parietal cells. In the management of patients with autoimmune diseases, AIG should be considered even if the endoscopy findings are normal.

Autoimmune Gastritis with a Long-term Course of Type B Gastritis: A Report of Two Cases

Autoimmune gastritis (AIG) typically exhibits the characteristics of type A gastritis and has been classified as a separate disease from type B gastritis that corresponds to Helicobacter pylori gastritis. However, many reports have suggested the involvement of H. pylori infection in the pathogenesis of AIG. In our two cases, the patients' previous gastritis exhibited a clear pattern in which H. pylori gastritis had progressed over many years, but ultimately transitioned to AIG with its spontaneous disappearance. These findings suggest that some cases of AIG might originate from long-standing H. pylori gastritis.

Diagnostic criteria and endoscopic and histological findings of autoimmune gastritis in Japan

The Japanese diagnostic criteria for autoimmune gastritis (AIG) were established by the "Study Group on the establishment of diagnostic criteria for type A gastritis," which is related to a workshop associated with the Japan Gastroenterological Endoscopy Society (JGES) and the Committee of AIG Research Group (CARP). The criteria were set as follows: the cases of confirmed diagnosis are patients in whom either the endoscopic or histological findings, or both, meet the requirements for AIG and who are confirmed to be positive for gastric autoantibodies (either anti-parietal cell or anti-intrinsic factor antibodies, or both). The presentation of endoscopic findings of early-stage AIG in the diagnostic criteria was withheld owing to the need for further accumulation and characterization of endoscopic clinical data. Therefore, diagnosis of early-stage AIG only requires histological confirmation and gastric autoantibody positivity. Suspected cases are patients in whom either the endoscopic or histological findings, or both, meet only the requirements for AIG. Histological findings only meet the requirements for early stage. AIG has been underdiagnosed in the past, but our study group's newly proposed diagnostic criteria will enable a more accurate and early diagnosis of AIG. The criteria can be used to stratify patients into various high-risk groups for gastric tumors and pernicious anemia. They would allow the establishment of an appropriate surveillance system in the coming years. Nevertheless, issues such as establishing the endoscopic findings of early-stage AIG and obtaining Japanese insurance coverage for gastric autoantibody tests require attention.

Clinical characteristics and endoscopic findings in autoimmune gastritis – A retrospective study

Objectives: Autoimmune gastritis (AG) is a rare condition that increases the risk of developing stomach adenocarcinomas or carcinoid tumours. The objectives of the present research were to summarise the clinical traits of AG patients, together with gastroscopic and histopatho-logic findings, demographic data, and hematologic characteristics.

Patients and methods: A medical centre assessed 58 AG patients from January 2019 to December 2022.

Results: The majority of the patients were female (73.7%), and the mean age of the participants at the time of the diagnosis was 57.7 ± 12.1 years. We identified pernicious anaemia (54.4%), iron deficiency anaemia (21.1%), as well as autoimmune disorders (96.5%). Though 78.9% of patients reported having gastrointestinal symptoms, 69% presented exclusively upper gastrointestinal symptoms, 17% only had lower, and 14% had concurrent upper and lower gastrointestinal symptoms. All 58 AG patients were examined for associated gastric lesions, although abnormal injuries were detected in only 22 of them. One patient (1.8%) had adenocarcinoma, while five patients (8.8%) had type 1 neuroendocrine tumours (NET). In addition, hyperplastic polyps were found in 16 (28.1%) individuals.

Conclusions: Other autoimmune diseases were present with AG, which showed a female predominance. Clinicians should give AG more significant thought by allowing access to interdisciplinary teams.

Incidence of Gastric Neoplasms Arising from Autoimmune Metaplastic Atrophic Gastritis: A Systematic Review and Case Reports

Autoimmune metaplastic atrophic gastritis (AMAG) is associated with an increased risk of gastric neoplasms. This study aimed to systematically analyze the incidence rate of gastric cancer (GC), low-grade dysplasia (LGD) and type-1 gastric neuroendocrine tumor (gNETs) development in AMAG adults. Studies on AMAG patients reporting the incidence of gastric neoplasms was identified through a systematic search in PUBMED and EMBASE. Study quality was assessed using the Joanna Briggs Institute quality assessment tool. Incidence rates of GC, LGD and type-1 gNETs were examined by meta-analysis. Thirteen studies met eligibility criteria. Incidence rate of gastric cancer calculated from the pooled data was 0.14% per person-year in both single-center studies and national registration studies. Meta-analysis showed a relative risk of 11.05 (95% CI: 6.39-19.11) for gastric cancer development in AMAG patients. The calculated pooled gastric LGD and type-1 gNETs incidence rates were 0.52% and 0.83% per person-year, respectively. As for experience from our center, we presented three distinctive cases of gastric neoplasm arising from the background of AMAG. This study underscores the potential for malignant transformation of precancerous lesions and reiterates the importance of careful esophagogastroduodenoscopy screening.

Examining the Diagnosis and Treatment Experiences of People Living With Autoimmune Gastritis and Pernicious Anemia

There is limited research evaluating the diagnosis and treatment of patients with autoimmune gastritis (AIG) and pernicious anemia (PA). We used a 2-phase data collection process to examine the literature and individual patient accounts. Phase one comprised a systematically conducted literature review focusing on diagnosis and treatment, relationships with healthcare practitioners and health-related quality of life (HRQOL). Phase two involved analysis of individual accounts via posts in online patient forums. We identified 6 main themes: the diagnosis journey, seeking treatment, patient-provider relationships, HRQOL, patient disempowerment, and the "expert patient." Our findings confirm significant knowledge gaps concerning AIG/PA across the healthcare community. These have a cascading effect starting with delays in diagnosis and poor treatment protocols and often lead to complete withdrawal from care seeking. The establishment of standard consensus guidelines and improved clinical awareness should be urgently addressed. Interventions that better help patients understand their illness are also needed to improve psychological health. Without these changes disengagement from health systems, and poor health outcomes, will continue for this population group.

Gastric lesions in patients with autoimmune metaplastic atrophic gastritis: a retrospective study in a single center

OBJECTIVES

The presence of autoimmune metaplastic atrophic gastritis (AMAG) may lead to an increased risk of associated gastric neoplastic lesions. This study aims to investigate the prevalence of gastric neoplasia in AMAG patients and to explore the possibility of PGI/II ratio as a predictor for AMAG diagnosis.

PATIENTS AND METHODS

Retrospective audit of 135 patients diagnosed with AMAG on endoscopic gastric biopsy between January 2017 and December 2020 at Beijing Friendship Hospital. The study was registered in Chinese Clinical Trial Registry (ChiCTR2000041163).

RESULTS

A total of 135 patients (the mean age 61.9 ± 10.9 years,109 female) had histologically confirmed AMAG. 31.1% (42/135) had AMAG without neoplasia on the initial biopsy; 37% (50/135) had multiple type 1 gastric neuroendocrine tumors (g-NETs), 36 grade 1 and 14 grade 2, the median diameter was 5 mm (range 1-25); 31.9% (43/135) had multiple gastric hyperplastic polyps (GHPs), including 15 cases of GHPs with neoplastic transformation, the median diameter was 14.5 mm (range 3-50). 3.7% (5/135) had single gastric low-grade dysplasia/adenoma, the median diameter was 5 mm (range 3-15). 5.9% (8/135) had single or double gastric high-grade dysplasia or adenocarcinoma, the median diameter was 15 mm (range 8-43). 40.7% (55/135) had pepsinogen (PG) I< 10 ng/ml, 45.9% (62/135) had PG I/II ratio ≤1 and each group had a median of PG I/II ratio <1.

CONCLUSIONS

Lower serum PG I level and PGI/II ratio may be a predictor to indicate the diagnosis of AMAG. It's necessary to perform regular endoscopic surveillance for AMAG patients to recognize associated gastric neoplasia timely.

The immune microenvironment in gastric adenocarcinoma

Like most solid tumours, the microenvironment of epithelial-derived gastric adenocarcinoma (GAC) consists of a variety of stromal cell types, including fibroblasts, and neuronal, endothelial and immune cells. In this article, we review the role of the immune microenvironment in the progression of chronic inflammation to GAC, primarily the immune microenvironment driven by the gram-negative bacterial species Helicobacter pylori. The infection-driven nature of most GACs has renewed awareness of the immune microenvironment and its effect on tumour development and progression. About 75-90% of GACs are associated with prior H. pylori infection and 5-10% with Epstein-Barr virus infection. Although 50% of the world's population is infected with H. pylori, only 1-3% will progress to GAC, with progression the result of a combination of the H. pylori strain, host susceptibility and composition of the chronic inflammatory response. Other environmental risk factors include exposure to a high-salt diet and nitrates. Genetically, chromosome instability occurs in ~50% of GACs and 21% of GACs are microsatellite instability-high tumours. Here, we review the timeline and pathogenesis of the events triggered by H. pylori that can create an immunosuppressive microenvironment by modulating the host's innate and adaptive immune responses, and subsequently favour GAC development.

Endoscopic Features of Autoimmune Gastritis: Focus on Typical Images and Early Images

Autoimmune gastritis (AIG) is chronic atrophic gastritis caused by an autoimmune mechanism of unknown etiology and presents with various pathological conditions by causing an achlorhydria state through parietal cell damage. The most characteristic endoscopic finding in AIG is advanced corpus-dominant mucosal atrophy. A recent study that examined several cases in Japan revealed the presence of endoscopic features other than corpus-dominant advanced atrophy. Remnants of oxyntic mucosa and sticky adherent dense mucus were found in ≥30% of cases, and hyperplastic polyps were found in ≥20% of cases. In image-enhanced endoscopy (IEE), white globe appearance (WGA) was observed in 32% of AIG cases. Additionally, some reports have stated that the findings in AIG cases using IEE showed cast-off skin appearance (CSA) and foveola type mucosa; however, a consensus is yet to be achieved. These endoscopic results were found in cases of advanced-stage AIG. There have been few reports concerning early-stage AIG cases. In these few reports, all of the cases were pathologically diagnosed as early AIG. In all of the cases, the pathological findings almost always showed neither parietal cell destruction nor atrophy. Endoscopic findings such as “mosaic pattern with slight swelling of the areae gastricae”, “diffuse reddened and edematous gastric fundic gland mucosa”, and “pseudopolyp-like nodules” may be common characteristics of early images. In such early cases, high antibody titers, no atrophic changes, and few clinical abnormal findings were shown. Endoscopists are expected to update their knowledge regarding AIG diagnosis with the evolution of imaging equipment.

Early autoimmune gastritis presenting with a normal endoscopic appearance

This report describes a patient with early-stage autoimmune gastritis (AIG) presenting with a normal endoscopic appearance. A 66-year-old man with autoimmune thyroiditis was suspected of having AIG because of a previous history of vitamin B12 deficiency when receiving steroid therapy for interstitial pneumonia 5 years earlier. At presentation, he tested positive for anti-parietal cell antibody (1:320) and anti-intrinsic factor antibody, but not for vitamin B12 deficiency. His gastrin level was elevated (338 pg/mL), but his pepsinogen (PG) I level (56.1 ng/mL) and PGI/PGII ratio (7.6) were normal. Endoscopically, neither atrophic nor inflammatory changes were observed. Histopathologic examination, however, showed mild atrophic changes with dense lymphocytic infiltration in the deep lamina propria and focal destruction of parietal cells in the greater curvature of the corpus. PGI-positive/MUC6-positive pseudo-pyloric metaplasia was observed in the area from which H+/K+-ATPase-positive parietal cells had disappeared. Chromogranin A immunostaining showed linear hyperplasia of enterochromaffin-like cells. By contrast, atrophic changes were not evident in the lesser curvature of the corpus, except for mild lymphocytic infiltration around and into the fundic glands. These serological and histopathological findings suggested that the patient had early-stage AIG with a normal endoscopic appearance.

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.