Natural history of autoimmune atrophic gastritis: a prospective, single centre, long-term experience

Unveiling Cancer-Related Metaplastic Cells in Both Helicobacter pylori Infection and Autoimmune Gastritis

BACKGROUND & AIMS

Gastric metaplasia may arise as a consequence of chronic inflammation and is associated with an increased risk of gastric cancer development. Although Helicobacter pylori (Hp) infection and autoimmune gastritis (AIG) both induce gastric metaplasia, possible distinctions in resulting metaplastic cells and their respective cancer risks requires further investigation.

METHODS

Using both mouse models and human participants, we scrutinized the metaplasia originating from Hp infection and AIG. Gastric pathology and metaplasia were examined through histopathologic assessment. Molecular features of metaplastic cells were defined using single-cell transcriptomics in murine models of Hp infection and AIG, as well as in human biopsy specimens from patients with Hp infection and AIG. Expression of a newly defined cancer-related metaplastic biomarker was confirmed through immunofluorescence.

RESULTS

Metaplasia in Hp infection and AIG displayed comparable histopathologic and transcriptional features. Diverse metaplastic subtypes were identified across both disease settings, with subtle differences in the prevalence of certain subtypes between inflammatory contexts. Notably, Hp infection did not drive a unique metaplastic cell phenotype. One metaplastic subtype, which resembled incomplete intestinal metaplasia and shared transcriptional features with gastric cancer, was identified in both diseases. This cancer-like metaplastic subtype was characterized by expression of the cancer-associated biomarker ANPEP/CD13.

CONCLUSION

Both Hp infection and AIG trigger a diverse array of metaplastic cell types. Identification of a cancer-related metaplastic cell uniquely expressing ANPEP/CD13, present in both Hp- and AIG-induced gastritis, indicates the carcinogenic capacity of both diseases. This discovery can guide early detection and risk stratification for patients with chronic gastritis.

Distinguishing Features of Autoimmune Gastritis Depending on Previous Helicobacter pylori Infection or Positivity to Anti-Parietal Cell Antibodies: Results From the Autoimmune gastRitis Italian netwOrk Study grOup (ARIOSO)

INTRODUCTION

To describe the clinical features and the risk of developing gastric tumors in patients with autoimmune gastritis (AIG).

METHODS

This was a retrospective, longitudinal, multicenter study conducted at 8 Italian tertiary referral centers. We retrieved clinical data from all histologically proven patients with AIG. Differences between Helicobacter pylori -exposed vs H. pylori -naive and anti-parietal cell antibody (PCA)-positive vs PCA-negative patients were investigated. The rate of gastric adenocarcinoma and type 1 gastric neuroendocrine neoplasm (gNEN) was assessed. A multivariable model for factors associated with gNEN was fitted.

RESULTS

A total of 1,598 patients with AIG (median age 58 years, interquartile range 46-68; F:M ratio 2.7:1) were included. H. pylori -naive patients were more likely to have a first-degree family history of AIG (14.7% vs 8.9%; P = 0.012), type 1 diabetes mellitus (4.9% vs 2.3%; P = 0.025), and pernicious anemia (30.9% vs 21.1%; P = 0.003). PCA-positive patients had significantly more associated autoimmune diseases (59.0% vs 42.9%; P < 0.001) and were more likely to have been diagnosed by a case-finding strategy (15.3% vs 2.6%; P < 0.001). Overall, 15 cases (0.9%) of gastric adenocarcinoma and 153 cases (9.6%) of gNEN occurred, with a global rate of 0.12 (95% confidence interval [CI] 0.07-0.20) and 1.22 (95% CI 1.03-1.42) per 100 person/year, respectively. Having a vitamin B12/iron deficiency manifestation at AIG diagnosis was associated with a 16.44 (95% CI 9.94-27.20 P < 0.001) hazard ratio of gNEN.

DISCUSSION

The "pure" AIG pattern has typical features of an autoimmune disease and seems to be unrelated to H. pylori . In a tertiary referral setting, the risk of developing overt gastric adenocarcinoma is low, while patients with vitamin B12 deficiency complications at onset may benefit from a more intense endoscopic follow-up for early gNEN detection.

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.

Serum Gastrin Levels Are Associated With Prevalent Neuroendocrine Tumors in Autoimmune Metaplastic Atrophic Gastritis

INTRODUCTION

Autoimmune metaplastic atrophic gastritis (AMAG) is a precancerous condition that predisposes to gastric neuroendocrine tumors (gNETs). There exist no methods to stratify patients with AMAG for gNET risk.

METHODS

We identified a cohort of patients with AMAG within a university health system using histopathologic and serologic criteria. We analyzed features predictive of prevalent gNET.

RESULTS

We identified 181 patients with AMAG and 41 (22.7%) with prevalent gNET. Gastrin levels were elevated in gNET (1,859.8 vs 679.5 pg/mL, P < 0.001), and gastrin titers demonstrated good discrimination (c = 0.799, 95% CI 0.707-0.892) for gNET.

DISCUSSION

Gastrin levels differ significantly between patients with AMAG with and without gNET.

Update understanding on diagnosis and histopathological examination of atrophic gastritis: A review

Chronic atrophic gastritis (CAG) is a complex syndrome in which long-term chronic inflammatory stimulation causes gland atrophy in the gastric mucosa, reducing the stomach's ability to secrete gastric juice and pepsin, and interfering with its normal physiological function. Multiple pathogenic factors contribute to CAG incidence, the most common being Helicobacter pylori infection and the immune reactions resulting from gastric autoimmunity. Furthermore, CAG has a broad spectrum of clinical manifestations, including gastroenterology and extra-intestinal symptoms and signs, such as hematology, neurology, and oncology. Therefore, the initial CAG evaluation should involve the examination of clinical and serological indicators, as well as diagnosis confirmation via gastroscopy and histopathology if necessary. Depending on the severity and scope of atrophy affecting the gastric mucosa, a histologic staging system (Operative Link for Gastritis Assessment or Operative Link on Gastritis intestinal metaplasia) could also be employed. Moreover, chronic gastritis has a higher risk of progressing to gastric cancer (GC). In this regard, early diagnosis, treatment, and regular testing could reduce the risk of GC in CAG patients. However, the optimal interval for endoscopic monitoring in CAG patients remains uncertain, and it should ideally be tailored based on individual risk evaluations and shared decision-making processes. Although there have been many reports on CAG, the precise etiology and histopathological features of the disease, as well as the diagnosis of CAG patients, are yet to be fully elucidated. Consequently, this review offers a detailed account of CAG, including its key clinical aspects, aiming to enhance the overall understanding of the disease.

Incidence of Gastric Adenocarcinoma in Those With Gastric Atrophy: A Systematic Review

Gastric atrophy (GA), or atrophic gastritis, is a pre-neoplastic lesion of gastric cancer (GC). It is part of the Correa cascade, which culminates in intestinal-type gastric adenocarcinoma. The cascade posits that intestinal-type gastric adenocarcinoma develops along a defined pathway of pre-neoplastic stages. The cascade begins with chronic gastritis, most commonly caused by Helicobacter pylori (H. pylori) infection, and proceeds through GA, gastric intestinal metaplasia (GIM), both complete and incomplete, dysplasia, both low and high-grade, and culminating in intestinal-type gastric adenocarcinoma. Attempts in Europe have been made to identify patients at risk of developing GC and target them with surveillance oesophagogastroduodenoscopy (OGD). However, there remains uncertainty about GA's risk of developing into GC. This poses issues in terms of guiding the need for and determining intervals for surveillance OGDs, which are a costly form of surveillance. As such, we attempted to gather all available studies assessing the risk of GC developing from GA, which is the first step in the Correa cascade. This study was a comprehensive systematic review of published papers, reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. This systematic review, which included a substantial 25,455 patients across 18 studies, found that the relative risk (RR) of GC in those with GA, using standardised incidence ratios as a measure of RR, was 15.1, with a 95% confidence interval ranging from 13.5 to 16.9. We conclude that GA does increase the risk of developing GC, and this risk may be higher than previously appreciated. Further large-scale studies are needed in Western cohorts of patients to precisely define this risk and guide the need for surveillance programs. These future studies must be standardised to account for H. pylori status, the topographical distribution of the GA, and the methods for assessing the degree of GA.

Vitamin B12 status in hospitalised cancer patients: Prevalence and clinical implications of depletion and hypervitaminosis

BACKGROUND & AIMS

The prevalence and clinical significance of vitamin B12 alterations in patients with cancer are poorly understood. We aimed to assess the prevalence and risk factors of vitamin B12 depletion or hypervitaminosis in patients with cancer.

METHODS

We retrospectively included hospitalised patients with cancer in 2017-2022. Plasma B12 levels were stratified as very low (VL, <200 pg/ml), low (L, 200-299 pg/ml), normal (N, 300-812 pg/ml), or high (H, ≥813 pg/ml). We collected demographic and several clinical data (e.g., comorbidities, nutritional status, ECOG-PS, cancer site and stage). Univariate and multivariate analyses for factors associated to the vitamin B12 status were fitted.

RESULTS

788 patients (F/M ratio 1.05, median age 72 years, [25th, 75th percentiles 62, 78 years]) were included. Vitamin B12 was VL in 14.1%, L in 19.4%, N in 49.4%, and H in 17.1% cases. Vitamin B12 distribution increased significantly as function of ECOG-PS levels. Patients with breast cancer were characterized by the highest median B12 value, while colorectal cancer patients by the lowest. Vitamin B12 was also significantly higher in advanced compared to early-stage patients as well as in those who had liver failure. Multivariate analysis showed that the probability of H vs. VL B12 levels was significantly increased in patients with hypoproteinemia, hypo-prealbuminemia, and ECOG-PS≥2, and decreased in those with colorectal and gastric cancer.

CONCLUSION

Vitamin B12 impairment is common in cancer patients. Increased vitamin B12 is associated with an impaired clinical status, while vitamin B12 depletion is more common in early-stage cancer and in elderly patients.

Occurrence and characteristics of endoscopic gastric polyps in patients with autoimmune gastritis (AGAPE study): A multicentric cross-sectional study

BACKGROUND

Autoimmune gastritis (AIG) leads to increased gastrin (G) levels due to hypo-achlorhydria, providing proliferative stimuli on the gastric mucosa.

AIMS

To evaluate the incidence and characteristics of gastric polyps in AIG patients across six tertiary centers in Italy.

METHODS

A multicentric, cross-sectional study enrolled patients with AIG diagnosed from January 2000 to June 2023, who underwent at least one endoscopy. Data on demographics, clinical history, biochemical profiles, and endoscopic and histopathological findings were systematically collected.

RESULTS

Among 612 AIG patients followed for a median of 4 years, 222 (36.3 %) developed at least one gastric polyp. Of these, 214 were non-endocrine lesions detected in 162 patients, including 151 inflammatory (70.5 %), 29 adenomatous (13.6 %), 18 fundic gland polyps (8.4 %), 13 adenocarcinomas (6.1 %), and one MALT lymphoma. Additionally, 108 patients had gastric neuroendocrine neoplasms (gNENs), with 48 also having non-endocrine polyps. Older age and higher gastrin and chromogranin A levels were associated with polyp occurrence. No differences in OLGA/OLGIM stages or Helicobacter pylori status were noted among patients with and without lesions.

CONCLUSION

This large multicentric study underscores the substantial occurrence of gastric polyps in AIG patients, including notable rates of gNENs and adenocarcinomas, emphasizing the importance of proactive endoscopic surveillance and histopathological examination for effective management.

Autoimmune Gastritis and Hypochlorhydria: Known Concepts from a New Perspective

Autoimmune atrophic gastritis is an immune-mediated disease resulting in autoimmune destruction of the specialized acid-producing gastric parietal cells. As a consequence, in autoimmune atrophic gastritis, gastric acid secretion is irreversibly impaired, and the resulting hypochlorhydria leads to the main clinical manifestations and is linked, directly or indirectly, to the long-term neoplastic complications of this disease. In the last few years, autoimmune atrophic gastritis has gained growing interest leading to the acquisition of new knowledge on different aspects of this disorder. Although reliable serological biomarkers are available and gastrointestinal endoscopy techniques have substantially evolved, the diagnosis of autoimmune atrophic gastritis is still affected by a considerable delay and relies on histopathological assessment of gastric biopsies. One of the reasons for the diagnostic delay is that the clinical presentations of autoimmune atrophic gastritis giving rise to clinical suspicion are very different, ranging from hematological to neurological-psychiatric up to gastrointestinal and less commonly to gynecological-obstetric symptoms or signs. Therefore, patients with autoimmune atrophic gastritis often seek advice from physicians of other medical specialties than gastroenterologists, thus underlining the need for increased awareness of this disease in a broad medical and scientific community.

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.

Gastric Carcinoma in Autoimmune Gastritis: A Histopathologic and Molecular Study

Patients with autoimmune gastritis (AIG) have a 13-fold risk of developing type-1 neuroendocrine tumors, whereas the risk for gastric adenocarcinoma is still uncertain. Here we describe the clinicopathologic and molecular features of a series of gastric carcinomas (GC) arising in the context of AIG. A total of 26 AIG-associated GC specimens were collected from 4 Italian Institutions. Immunohistochemistry for MUC1, MUC2, MUC5AC, MUC6, CDX2, HER2, PD-L1, CLDN18, mismatch repair (MMR) proteins, and p53 and EBV-encoded RNA (EBER) in situ hybridization were performed. Histologic and immunohistochemical features were jointly reviewed by 5 expert gastrointestinal pathologists. Next-generation sequencing analysis (TrueSight Oncology 500, Illumina) of 523 cancer-related genes was performed on 19 cases. Most tumors were diagnosed as pT1 (52%) and they were located in the corpus/fundus (58%) and associated with operative link for gastritis assessment stage II gastritis (80.8%), absence of parietal cells, complete intestinal metaplasia, and enterochromaffin-like-cell micronodular hyperplasia. Only 4 (15.4%) GCs were diagnosed during follow-up for AIG. The following histotypes were identified: 20 (77%) adenocarcinomas; 3 (11%) mixed neuroendocrine-non-neuroendocrine neoplasms, and 2 (8%) high-grade solid adenocarcinomas with focal neuroendocrine component, 1 (4%) adenocarcinoma with an amphicrine component. Overall, 7 cases (27%) showed MMR deficiency, 3 (12%) were positive (score 3+) for HER2, 6 (23%) were CLDN18 positive, and 11 (42%) had PD-L1 combined positive score ≥ 10. EBER was negative in all cases. Molecular analysis revealed 5/19 (26%) microsatellite instability (MSI) cases and 7 (37%) tumor mutational burden (TMB) high. The most frequently altered genes were TP53 (8/19, 42%), RNF43 (7/19, 37%), ERBB2 (7/19, 37% [2 amplified and 5 mutated cases]), ARID1A (6/19, 32%), and PIK3CA (4/19, 21%). In summary, AIG-associated GCs are often diagnosed at low stage in patients with longstanding misrecognized severe AIG; they often display a neuroendocrine component or differentiation, have relatively higher rates of MMR deficiency, and TMB high.

Long-Term Natural History of Autoimmune Gastritis: Results From a Prospective Monocentric Series

INTRODUCTION

The natural history of autoimmune gastritis (AIG) has been poorly described. In this study, we report the long-term natural history and clinical clustering of the full spectrum of AIG, from the potential to the complicated stage.

METHODS

Prospective single-center study conducted in a tertiary referral center. Patients with AIG at any stage (0 = potential; 1 = early; 2 = florid; 3 = severe; and 4 = complicated) were enrolled (January 2000-December 2022). The histopathological evolution, the clinical presentation, and the correlates of evolution of potential AIG were assessed.

RESULTS

Four hundred ninety-eight patients with AIG (mean age 56.7 ± 15.2 years, F:M ratio 2.5:1) were included, of whom 93 experienced potential AIG. The maximum disease duration was 27 years (median 18, interquartile range 14-23), while the overall median follow-up was 52 months (interquartile range 12-95). Age was significantly lower in stage 0 compared with that in the other stages. Accidental histologic evidence and hematologic findings were the most common clusters of diagnosis. The overall median rate of progression was 7.29 per 100 persons/yr (95% confidence interval [CI] 6.19-8.59), while the stage-specific rates of progression were 10.85 (stage 0; 95% CI 7.75-15.18), 14.83 (stages 1-2; 95% CI 11.89-18.49), and 2.68 (stage 3; 95% CI 1.88-3.84). Newly onset neoplastic complications at follow-up occurred in 41/483 patients (8.5%; 23 neuroendocrine tumors and 18 epithelial dysplasia). No cases of adenocarcinoma were noticed. Male sex was associated with a greater likelihood of evolving from potential AIG to overt AIG.

DISCUSSION

AIG is a progressive disorder, with a virtually absent risk of gastric adenocarcinoma. Patients with potential AIG should be monitored because they carry a high risk of evolving into overt AIG.

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.

Incidence and Predictors of Gastric Neoplastic Lesions in Corpus-Restricted Atrophic Gastritis: A Single-Center Cohort Study

INTRODUCTION

Corpus-restricted atrophic gastritis is a chronic inflammatory disorder leading to possible development of type 1 neuroendocrine tumors (T1gNET), intraepithelial neoplasia (IEN), and gastric cancer (GC). We aimed to assess occurrence and predictors of gastric neoplastic lesions in patients with corpus-restricted atrophic gastritis at long-term follow-up.

METHODS

A prospective single-center cohort of patients with corpus-restricted atrophic gastritis adhering to endoscopic-histological surveillance was considered. Follow-up gastroscopies were scheduled according to the management of epithelial precancerous conditions and lesions of the stomach guidelines. In case of new/worsening of known symptoms, gastroscopy was anticipated. Cox regression analyses and Kaplan-Meier survival curves were obtained.

RESULTS

Two hundred seventy-five patients with corpus-restricted atrophic gastritis (72.0% female, median age 61 [23-84] years) were included. At a median follow-up of 5 (1-17) years, the annual incidence rate person-year was 0.5%, 0.6%, 2.8%, and 3.9% for GC/high-grade IEN, low-grade IEN, T1gNET, and all gastric neoplastic lesions, respectively. All patients showed at baseline operative link for gastritis assessment (OLGA)-2, except 2 low-grade (LG) IEN patients and 1 T1gNET patient with OLGA-1. Age older than 60 years (hazard ratio [HR] 4.7), intestinal metaplasia without pseudopyloric metaplasia (HR 4.3), and pernicious anemia (HR 4.3) were associated with higher risk for GC/HG-IEN or LG-IEN development and shorter mean survival time for progression (13.4, 13.2, and 11.1, respectively, vs 14.7 years, P = 0.01). Pernicious anemia was an independent risk factor for T1gNET (HR 2.2) and associated with a shorter mean survival time for progression (11.7 vs 13.6 years, P = 0.04) as well as severe corpus atrophy (12.8 vs 13.6 years, P = 0.03).

DISCUSSION

Patients with corpus-restricted atrophic gastritis are at increased risk for GC and T1gNET despite low-risk OLGA scores, and those aged older than 60 years with corpus intestinal metaplasia or pernicious anemia seem to display a high-risk scenario.

Treatment with IgG Fc fragments bearing regRF epitopes prevents destruction of the gastric mucosa in experimental autoimmune gastritis model

Autoimmune gastritis (AIG) is the autoimmune disease of the stomach characterized by the destruction of the oxyntic mucosa, which stops producing acid and becomes both functionally and morphologically atrophic. There is no specific treatment for AIG. Previously, we identified a new immunoregulatory factor (regulatory rheumatoid factor (regRF)), the stimulation production of which reduces certain experimental autoimmune diseases. Epitopes specific to the regulatory rheumatoid factor (regRF epitopes) can be obtained on IgG Fc fragments. In the rat AIG model, the therapeutic efficacy of IgG Fc fragments bearing regRF epitopes was tested. Treatment with IgG Fc fragments bearing regRF epitopes reduced T lymphocytic infiltration of oxyntic mucosa and prevented its damage in the AIG rat model, while in rats treated with placebo, T lymphocytic infiltration of the mucosa, loss of parietal cells, including severe were observed. Therefore, IgG Fc fragments bearing regRF epitopes are a potential therapeutic agent for treating autoimmune gastritis in its early stages.

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.

Rat Experimental Autoimmune Gastritis Model

BACKGROUND

Autoimmune gastritis (AIG) is an autoimmune disease of the stomach characterized by the destruction of the oxyntic mucosa, which stops producing acid and becomes both functionally and morphologically atrophic. The pathogenic mechanisms behind the disease are still poorly understood. There is no early diagnosis and specific AIG therapy. To elucidate the pathogenesis of AIG, to search for early diagnostic markers, as well as to test new therapeutic approaches, an adequate and easily reproducible experimental model for autoimmune gastritis (EAG) is needed. Existing EAG models have some limitations, including slow development of signs, absence of advanced gastritis, irrational use of animals to obtain antigen. The aim was to find out whether it is possible to cause autoimmune gastritis similar to human disease in Wistar rats through immunization with a homologous gastric mucosa extract.

METHODS

Wistar rats were immunized with gastric mucosa extract. Histology studies and evaluation of serological parameters were performed 56 and 91 days later.

RESULTS

Destruction of oxyntic glands by infiltrating T lymphocytes were detected in rats on 56 and 91 days after initial immunization with gastric mucosa extract. Hyperplasia of enterochromaffin-like (ECL) cells was detected on the 91st day. Antral mucosa remained unchanged.

CONCLUSION

Wistar rats, immunized with gastric mucosa extract, developed EAG similar to human AIG. The advantages of received EAG model are the ease of obtaining, the rapid development of oxyntic mucosa damage, which may progress to ECL cell hyperplasia.

The central role of gastrin in gastric cancer

The prevalence of gastric cancer has markedly declined, but due to the high mortality rates associated with gastric cancer, it is still a serious disease. The preferred classification of gastric cancer is according to Lauren into either the intestinal type, which has a glandular growth pattern, or the diffuse type, which does not have glandular structures. Both types have been classified as adenocarcinomas, with the latter type based on periodic acid-Schiff (PAS) positivity presumed to reflect mucin. However, the presence of mucin in the diffuse type, in contrast to neuroendocrine/enterochromaffin-like (ECL) cell markers, has not been confirmed by immunohistochemistry and in situ hybridization. The ECL cells are probably prone to becoming cancerous because they do not express E-cadherin. Gastric cancer is unique in that a bacterium, Helicobacter pylori, is thought to be its main cause. H. pylori predisposes infected individuals to cancer only after having caused oxyntic atrophy leading to gastric hypoacidity and hypergastrinemia. No single H. pylori factor has been convincingly proved to be carcinogenic. It is probable that gastrin is the pathogenetic factor for gastric cancer due to H. pylori, autoimmune gastritis, and long-term prolonged inhibition of gastric acid secretion. Hypergastrinemia induces ECL cell hyperplasia, which develops into neuroendocrine tumors (NETs) and then into neuroendocrine carcinomas in rodents, a sequence that has also been described in humans. During carcinogenesis, the tumor cells lose specific traits, requiring that sensitive methods be used to recognize their origin. Gastric cancer occurrence may hopefully be prevented by H. pylori eradication at a young age, and by the reduced use of inhibitors of acid secretion and use of a gastrin antagonist in those with previous long-term H. pylori infection and those with autoimmune gastritis.

Update on Serum Biomarkers in Autoimmune Atrophic Gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a persistent, corpus-restricted immune-mediated destruction of the gastric corpus oxyntic mucosa with reduced gastric acid and intrinsic factor secretion, leading to iron deficiency and pernicious anemia as a consequence of iron and cobalamin malabsorption. Positivity toward parietal cell (PCA) and intrinsic factor (IFA) autoantibodies is very common. AAG may remain asymptomatic for many years, thus making its diagnosis complex and often delayed. Due to the increased risk of gastric neoplasms, a timely diagnosis of AAG is clinically important.

CONTENT

The gold standard for AAG diagnosis is histopathological assessment of gastric biopsies obtained during gastroscopy, but noninvasive, preendoscopic serological screening may be useful in some clinical scenarios. Serum biomarkers for AAG may be divided into 2 groups: gastric autoimmunity-related biomarkers, such as PCA and IFA, and gastric corpus atrophy/reduced gastric acid secretion-related biomarkers, such as serum gastrin and pepsinogens. The present review focuses on the clinical significance and pitfalls of serum biomarkers related to gastric autoimmunity and gastric corpus atrophy, including some discussion of analytical methods.

SUMMARY

Serum assays for PCA, IFA, gastrin, and pepsinogen I show good diagnostic accuracy for noninvasive diagnostic work-up of AAG. Diagnostic performance may increase by combining >1 of these tests, overcoming the problem of seronegative AAG. However, appropriately designed, comparative studies with well-characterized patient cohorts are needed to better define the reliability of these biomarkers in the diagnosis of patients with AAG. Currently, positive serum tests should always be followed by the state-of-art diagnostic test, that is, histopathological assessment of gastric biopsies obtained during gastroscopy to definitively confirm or rule out AAG and eventually neoplastic complications.

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.

Exploring the spectrum of incidental gastric polyps in autoimmune gastritis

BACKGROUND

Gastric polyps represent an abnormal proliferation of the gastric mucosa. Chronic atrophic autoimmune gastritis (CAAG) targets parietal cells and results in hypo-achlorhydria and hypergastrinemia, which exerts a proliferative effect on the gastric mucosa.

AIMS

We investigate the incidence of gastric polyps in CAAG patients.

METHODS

This is a single-center retrospective study examining patients with confirmed CAAG from January 1990 until June 2022. Demographic, clinical, biochemical, and serological data were collected for each included patient. The histopathological characteristics of the detected polyps were recorded.

RESULTS

A total of 176 CAAG patients were included. Eighty-nine (50.5%) had 163 incidental polyps. Seventy-six patients (85%) had 130 non-endocrine lesions, among which 118 (90.7%) were inflammatory, 6 (4.6%) adenomatous, and 4 (3%) fundic; 33 patients (37%) had gastric neuroendocrine neoplasms (gNENs), and 21 (23.6%) both; one had MALToma and one gastric adenocarcinoma. Higher circulating levels of gastrin and chromogranin A were observed among patients with polyps (median 668 vs 893 pg/ml p = 0.0237, 146 vs 207 ng/ml p = 0.0027, respectively).

CONCLUSION

CAAG implies a high incidence of gNENs and exocrine lesions. Gastrin plays a possible trophic role on the mucosa. Further evidence is needed to validate its predictive role for increased polyp risk in CAAG.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

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.

Gastric Microbiota Gender Differences in Subjects with Healthy Stomachs and Autoimmune Atrophic Gastritis

Gender differences and microbiota are gaining increasing attention. This study aimed to assess gender differences in gastric bacterial microbiota between subjects with healthy stomachs and those with autoimmune atrophic gastritis. This was a post hoc analysis of 52 subjects undergoing gastroscopy for dyspepsia (57.7% healthy stomach, 42.3% autoimmune atrophic gastritis). Gastric biopsies were obtained for histopathology and genomic DNA extraction. Gastric microbiota were assessed by sequencing the hypervariable regions of the 16SrRNA gene. The bacterial profile at the phylum level was reported as being in relative abundance expressed as 16SrRNA OTUs (>0.5%) and biodiversity calculated as Shannon-diversity index-H. All data were stratified for the female and male gender. Results showed that women with healthy stomachs had a higher gastric bacterial abundance and less microbial diversity compared to men. Likely due to hypochlorhydria and the non-acid intragastric environment, autoimmune atrophic gastritis seems to reset gender differences in gastric bacterial abundance and reduce biodiversity in males, showing a greater extent of dysbiosis in terms of reduced biodiversity in men. Differences between gender on taxa frequency at the phylum and genus level in healthy subjects and autoimmune atrophic gastritis were observed. The impact of these findings on the gender-specific natural history of autoimmune atrophic gastritis remains to be elucidated; in any case, gender differences should deserve attention in gastric microbiota studies.

Autoimmune gastritis and stomach cancer: assessing the risks

The purpose of this publication is to systematize available data on the risks of developing stomach cancer in patients with a chronic autoimmune gastritis with a demonstration of the clinical case of a patient with a chronic autoimmune gastritis and a neuroendocrine gastric tumor of the type 1. Discussion: the article discusses the risks of stomach cancer in patients with chronic autoimmune gastritis. A mechanism for the formation of a neuroendocrine gastric tumor of the type 1, associated with autoimmune gastritis, is given. A clinical example of a patient with a long history of dyspepsia, the presence of concomitant changes in the results of laboratory tests, describes an algorithm for diagnosis of autoimmune gastritis and associated neuroendocrine tumors. The risks of the development in patients with autoimmune gastritis of formidable complications as an adenocarcinoma of the stomach are considered. Conclusion: Chronic autoimmune gastritis is a precancerous diseases of the stomach, with the progressive atrophy of the gastric body mucosa, and associated with an increased risk of developing neuroendocrine gastric tumor of the type 1 and adenocarcinoma of the stomach. Patients with autoimmune gastritis need dynamic outpatient observation, with endoscopic control and assessment of the degree and stage of gastritis in OLGA system, with immunogistochemistry to evaluate the risks of stomach cancer and timely implementation of the necessary measures of carcinoprection.

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.

Endoscopic techniques for gastric neuroendocrine tumors: An update

Gastric neuroendocrine neoplasms (gNENs) are a rare type of gastric neoplasm, even if their frequency is increasing according to the latest epidemiologic revisions of the main registries worldwide. They are divided into three main subtypes, with different pathogeneses, biological behaviors, and clinical characteristics. GNEN heterogeneity poses challenges, therefore these neoplasms require different management strategies. Update the knowledge on the endoscopic treatment options to manage g-NENs. This manuscript is a narrative review of the literature. In recent years, many advances have been made not only in the knowledge of both the pathogenesis and the molecular profiling of gNENs but also in the endoscopic expertise towards innovative treatment options, which proved to be less aggressive without losing the capability of being radical. The endoscopic approach is increasingly applied in the field of gastrointestinal (GI) luminal neoplasms, and this is true not only for adenocarcinomas but also for gNENs. In particular, different techniques have been described for the endoscopic removal of suspected lesions, ranging from classical polypectomy (cold or hot snare) to endoscopic mucosal resection (both with “en bloc” or piecemeal technique), endoscopic submucosal dissection, and endoscopic full-thickness resection. GNENs comprise different subtypes of neoplasms with distinct management and prognosis. New endoscopic techniques offer a wide variety of approaches for GI localized neoplasms, which demonstrated to be appropriate and effective also in the case of gNENs. Correct evaluation of size, site, morphology, and clinical context allows the choice of tailored therapy in order to guarantee a definitive treatment.

Chronic atrophic gastritis in different ages in South China: a 10-year retrospective analysis

OBJECTIVES

To explore the prevalence, characteristics, age distribution and etiology changes of chronic atrophic gastritis (CAG) in South China.

METHODS

This study included all patients who underwent endoscopy examinations from 2011 to 2020 in our hospital. Patients were divided into groups 1 (2011-2015) and 2 (2016-2020). The prevalence, characteristics, age distribution and etiology changes of CAG were compared between groups.

RESULTS

Overall CAG prevalence was 20.92% (24,084/115,110) from 2011 to 2020; prevalence significantly differed between groups (18.78%, 8468/45,087, in group 1 and 22.30%, 15,616/70,023, in group 2). Patients with CAG had significantly younger age (under 45) and more corpus atrophy and more autoimmune atrophic gastritis (AAG) in group 2 than in group 1. AAG prevalence in group 2 was 30.11% (4702/15,616) significantly higher than 13.57% (1149/8468) in group 1. 82 patients with AAG later exhibited gastric cancer without obvious clinical features over the decade.

CONCLUSIONS

CAG is increasing and seems starting earlier among people during the study period. We need to focus on diagnosis and treatment of corpus related atrophy and AAG, especially for the young. Laboratory examination, endoscopic biopsy and surveillance are important for CAG.

A DSC Test for the Early Detection of Neoplastic Gastric Lesions in a Medium-Risk Gastric Cancer Area

In this study, we aimed to assess the accuracy of the proposed novel, noninvasive serum DSC test in predicting the risk of gastric cancer before the use of upper endoscopy. To validate the DSC test, we enrolled two series of individuals living in Veneto and Friuli-Venezia Giulia, Italy (n = 53 and n = 113, respectively), who were referred for an endoscopy. The classification used for the DSC test to predict gastric cancer risk combines the coefficient of the patient's age and sex and serum pepsinogen I and II, gastrin 17, and anti-Helicobacter pylori immunoglobulin G concentrations in two equations: Y1 and Y2. The coefficient of variables and the Y1 and Y2 cutoff points (>0.385 and >0.294, respectively) were extrapolated using regression analysis and an ROC curve analysis of two retrospective datasets (300 cases for the Y1 equation and 200 cases for the Y2 equation). The first dataset included individuals with autoimmune atrophic gastritis and first-degree relatives with gastric cancer; the second dataset included blood donors. Demographic data were collected; serum pepsinogen, gastrin G17, and anti-Helicobacter pylori IgG concentrations were assayed using an automatic Maglumi system. Gastroscopies were performed by gastroenterologists using an Olympus video endoscope with detailed photographic documentation during examinations. Biopsies were taken at five standardized mucosa sites and were assessed by a pathologist for diagnosis. The accuracy of the DSC test in predicting neoplastic gastric lesions was estimated to be 74.657% (65%CI; 67.333% to 81.079%). The DSC test was found to be a useful, noninvasive, and simple approach to predicting gastric cancer risk in a population with a medium risk of developing gastric cancer.

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.

Comparative morphological characteristics of helicobacter pylori and autoimmune gastritis

Objective: to conduct a comparative morphological analysis of helicobacter pylori (H. pylori) and autoimmune gastritis and to determine the significant morphological criteria for differential diagnosis.

Materials and methods. 30 cases of chronic atrophic helicobacter gastritis and 30 cases of chronic atrophic autoimmune gastritis were retrospectively selected for the study. In all cases of helicobacter gastritis, the presence of H. pylori was confirmed by morphological diagnostic methods using Giemsa staining or additionally using immunohistochemistry. All cases of autoimmune gastritis were additionally confirmed by clinical and laboratory diagnostic methods, some patients had a long history of follow-up and biopsy material was taken from them repeatedly. A prerequisite was taking at least 5 biopsies according to the Sydney Protocol.

Results. The main differential diagnostic feature in our study was the detection of H. pylori, as well as the localization of the lesion in the stomach body characteristic of autoimmune gastritis and in the antrum in helicobacter gastritis. The study groups differed by gender (the predominance of females in the group of autoimmune gastritis), the prevalence and activity of inflammation (all cases of helicobacter gastritis had signs of inflammation activity). When studying the content of neuroendo-crine cells in cases of helicobacter gastritis in the stomach body, simple hyperplasia of neuroendocrine cells was noted, in cases of au-toimmune gastritis, the appearance of chains and nodules was noted, which corresponded to linear and nodular hyperplasia of neuro-endocrine cells.

Conclusion. The morphological criteria obtained in the study make it possible to make a differential diagnosis between helicobacter and autoimmune gastritis. This is extremely important because of the differences in treatment approaches and dynamic monitoring tactics in these variants of chronic gastritis.

Kyoto classification of gastritis, virtual chromoendoscopy and artificial intelligence: Where are we going? What do we need?

Chronic gastritis (CG) is a widespread and frequent disease, mainly caused by Helicobacter pylori infection, which is associated with an increased risk of gastric cancer. Virtual chromoendoscopy improves the endoscopic diagnostic efficacy, which is essential to establish the most appropriate therapy and to enable cancer prevention. Artificial intelligence provides algorithms for the diagnosis of gastritis and, in particular, early gastric cancer, but it is not yet used in practice. Thus, technological innovation, through image resolution and processing, optimizes the diagnosis and management of CG and gastric cancer. The endoscopic Kyoto classification of gastritis improves the diagnosis and management of this disease, but through the analysis of the most recent literature, new algorithms can be proposed.

Autoimmune gastritis: long-term natural history in naïve Helicobacter pylori-negative patients

OBJECTIVE

Autoimmune gastritis (AIG) is an immunomediated disease targeting parietal cells, eventually resulting in oxyntic-restricted atrophy. This long-term follow-up study aimed at elucidating the natural history, histological phenotype(s), and associated cancer risk of patients with AIG consistently tested H. pylori-negative (naïve H. pylori-negative subjects).

DESIGN

Two-hundred eleven naïve H. pylori-negative patients (tested by serology, histology, molecular biology) with AIG (F:M=3.15:1; p<0.001) were prospectively followed up with paired biopsies (T1 vs T2; mean follow-up years:7.5 (SD:4.4); median:7). Histology distinguished non-atrophic versus atrophic AIG. Atrophy was further subtyped/scored as non-metaplastic versus metaplastic (pseudopyloric (PPM) and intestinal (IM)). Enterochromaffin-like-cell (ECL) status was categorised as diffuse versus adenomatoid hyperplasia/dysplasia, and type 1 neuroendocrine tumours (Type1-NETs).

RESULTS

Over the long-term histological follow-up, AIG consistently featured oxyntic-predominant-mononuclear inflammation. At T1, PPM-score was greater than IM (200/211 vs 160/211, respectively); IM scores increased from T1 to T2 (160/211 to 179/211), with no changes in the PPM prevalence (T1=200/211; T2=201/211). At both T1/T2, the prevalence of OLGA-III-stage was <5%; no Operative Link on Gastritis Assessment (OLGA)-IV-stage occurred. ECL-cell-status progressed from diffuse to adenomatoid hyperplasia/dysplasia (T1=167/14 vs T2=151/25). Type1-NETs (T1=10; T2=11) always coexisted with extensive oxyntic-atrophy, and ECL adenomatoid-hyperplasia/dysplasia. No excess risk of gastric or other malignancies was found over a cumulative follow-up time of 10 541 person years, except for (marginally significant) thyroid cancer (SIR=3.09; 95% CI 1.001 to 7.20).

CONCLUSIONS

Oxyntic-restricted inflammation, PPM (more than IM), and ECL-cell hyperplasia/neoplasia are the histological AIG hallmarks. Compared with the general population, corpus-restricted inflammation/atrophy does not increase the GC risk. The excess of GC risk reported in patients with AIG could plausibly result from unrecognised previous/current H. pylori comorbidity.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

Seronegative autoimmune diseases: A challenging diagnosis

Autoimmune diseases (AID) are increasingly prevalent conditions which comprise more than 100 distinct clinical entities that are responsible for a great disease burden worldwide. The early recognition of these diseases is key for preventing their complications and for tailoring proper management. In most cases, autoantibodies, regardless of their potential pathogenetic role, can be detected in the serum of patients with AID, helping clinicians in making a definitive diagnosis and allowing screening strategies for early -and sometimes pre-clinical- diagnosis. Despite their undoubted crucial role, in a minority of cases, patients with AID may not show any autoantibody, a condition that is referred to as seronegative AID. Suboptimal accuracy of the available laboratory tests, antibody absorption, immunosuppressive therapy, immunodeficiencies, antigen exhaustion, and immunosenescence are the main possible determinants of seronegative AID. Indeed, in seronegative AID, the diagnosis is more challenging and must rely on clinical features and on other available tests, often including histopathological evaluation and radiological diagnostic tests. In this review, we critically dissect, in a narrative fashion, the possible causes of seronegativity, as well as the diagnostic and management implications, in several AID including autoimmune gastritis, celiac disease, autoimmune liver disease, rheumatoid arthritis, autoimmune encephalitis, myasthenia gravis, Sjögren's syndrome, antiphospholipid syndrome, and autoimmune thyroid diseases.

Mucosal Overexpression of Thymic Stromal Lymphopoietin and Proinflammatory Cytokines in Patients With Autoimmune Atrophic Gastritis

INTRODUCTION

The immune mechanisms underlying human autoimmune atrophic gastritis (AAG) are poorly understood. We sought to assess immune mucosal alterations in patients with AAG.

METHODS

In 2017-2021, we collected gastric corpus biopsies from 24 patients with AAG (median age 62 years, interquartile range 56-67, 14 women), 26 age-matched and sex-matched healthy controls (HCs), and 14 patients with Helicobacter pylori infection (HP). We investigated the lamina propria mononuclear cell (LPMC) populations and the mucosal expression of thymic stromal lymphopoietin (TSLP) and nicotinamide phosphoribosyltransferase (NAMPT). Ex vivo cytokine production by organ culture biopsies, under different stimuli (short TSLP and zinc-l-carnosine), and the gastric vascular barrier through plasmalemma vesicle-associated protein-1 (PV1) were also assessed.

RESULTS

In the subset of CD19+ LPMC, CD38+ cells (plasma cells) were significantly higher in AAG compared with HC. Ex vivo production of tumor necrosis factor (TNF)-α, interleukin (IL)-15, and transforming growth factor β1 was significantly higher in AAG compared with HC. At immunofluorescence, both IL-7R and TSLP were more expressed in AAG compared with HC and HP, and short TSLP transcripts were significantly increased in AAG compared with HC. In the supernatants of AAG corpus mucosa, short TSLP significantly reduced TNF-α, while zinc-l-carnosine significantly reduced interferon-γ, TNF-α, IL-21, IL-6, and IL-15. NAMPT transcripts were significantly increased in AAG compared with HC. PV1 was almost absent in AAG, mildly expressed in HC, and overexpressed in HP.

DISCUSSION

Plasma cells, proinflammatory cytokines, and altered gastric vascular barrier may play a major role in AAG. TSLP and NAMPT may represent potential therapeutic targets, while zinc-l-carnosine may dampen mucosal inflammation.

Increase of Deep Intraepithelial Lymphocytes in the Oxyntic Mucosa of Patients With Potential and Overt Autoimmune Gastritis

Pathological correlates of potential autoimmune gastritis (AIG), defined by anti-parietal cell antibody (PCA) positivity in the absence of gastric atrophy, have never been described. We herein aimed to assess intraepithelial lymphocyte (IEL) infiltration in gastric corpus of AIG patients. From 2000 to 2021, among 53 potential AIG patients, we focused on nine (median age 61 years, IQR 53-82; four females) who subsequently developed overt AIG. IEL infiltration of the oxyntic mucosa was assessed before and after developing overt AIG by measuring deep and superficial CD3+ IEL. AIG patients with different degrees of corpus atrophy, healthy controls (HC), active H. pylori gastritis, celiac disease (CD), and Hashimoto’s thyroiditis patients were included as controls. Of note, deep, but not superficial, CD3+ IEL count was higher (p<0.001) in potential AIG compared to HC and H. pylori gastritis. Deep CD3+ IEL infiltration did not change before or after the evolution into atrophy (median 9.6, IQR 8.8-12.4, vs 11.3, IQR 9.4-12.9). No difference was found in deep CD3+ IEL infiltration among potential, mild, and severe AIG, and compared to Hashimoto’s thyroiditis or CD. A deep CD3+ IEL cut-off of >7/100 epithelial cells allowed discrimination of any AIG stage and severity (AUC=0.842). We conclude that an increased deep CD3+ IEL infiltration of the oxyntic mucosa could represent a marker of potential AIG. Prospective studies including a larger number of potential AIG patients are needed.

Case Report: Two Is Not (Always) Better Than One: Pyloric Gland Adenoma of the Gastric Cardia and Concurrent Neuroendocrine Cell Dysplasia Arising From Autoimmune Gastritis

Autoimmune gastritis is a chronic immune-mediated disorder characterized by varied clinical manifestations and that should be endoscopically managed over time, as the gastric atrophy contributes to microenvironmental alterations of the stomach milieu, and an increased cancer risk has been linked to this condition. Here, we report the unusual case of a woman who developed a cardiac high-grade pyloric adenoma in a context of previously undiagnosed autoimmune gastritis with synchronous neuroendocrine cell hyperplastic and dysplastic lesions.

Venous thromboembolism in chronic gastrointestinal disorders

INTRODUCTION

Chronic gastrointestinal disorders (including autoimmune gastritis, celiac disease, inflammatory bowel disease, and diverticular disease) are highly prevalent disorders, that may be associated with unpredictable, life-threatening complications, such as thromboembolic events. Venous thromboembolism (VTE) is one of the major causes of morbidity and mortality worldwide. Several conditions, including cancer, major trauma, surgery, prolonged immobilization, are well-established risk factors for VTE. Over the past decade, chronic inflammation has also been identified as an independent risk factor for VTE due to the prothrombotic effects of inflammatory cytokines and oxidative stress on the coagulation cascade. Other several mechanisms were shown to be associated with a higher incidence of VTE in patients with gastrointestinal disorders.

AREAS COVERED

We critically discuss the latest insights into the mechanisms responsible for thromboembolic manifestations in chronic gastrointestinal disorders, also focusing on the recognition of risk factors and treatment.

EXPERT OPINION

The occurrence of thrombotic complications is underestimated in patients with chronic gastrointestinal disorders. Identifying potential risk factors and concomitant predisposing conditions and to prevent VTE and guide treatment require a multidisciplinary approach, and this is critically important for clinicians, in order to provide the best care for such patients.

Time course and risk factors of evolution from potential to overt autoimmune gastritis

BACKGROUND

The natural history of patients with potential autoimmune gastritis (AIG), defined by the presence of serum anti-parietal cell antibody (PCA) positivity and no gastric histopathological alterations, is unknown. We therefore aimed to assess the natural history and clinical correlates of potential autoimmune gastritis (AIG).

METHODS

In 2000-2019, we enrolled potential AIG patients by monitoring once a year (±6 months) histopathological evolution into overt AIG, defined as the occurrence of atrophy in the oxyntic mucosa. Factors affecting disease progression were assessed.

RESULTS

Fifty-one potential AIG patients (median age 57 years, IQR 43-73, F:M ratio 1.7:1) were monitored for up to 15 years (median 6 years, IQR 3-8). Of them, 24 (47.1%) evolved into overt AIG in a median time of 2 years (IQR 2-4.5). Having a concomitant autoimmune disorder (HR 4.09, 95% CI 1.52-11.00; p = 0.005), but not older age (HR 1.00, 95% CI 0.45-2.22; p = 0.992) and female sex (HR 1.19, 95% CI 0.51-2.78; p = 0.395), was associated with evolution into overt AIG.

CONCLUSIONS

Roughly one in two potential AIG patients will evolve into overt AIG over a median time of two years, especially those with a concurrent autoimmune disorder.

Relevance of pepsinogen, gastrin, and endoscopic atrophy in the diagnosis of autoimmune gastritis

Simple objective modalities are required for evaluating suspected autoimmune gastritis (AIG). This cross-sectional study aimed to examine whether pepsinogen, gastrin, and endoscopic findings can predict AIG. The diagnostic performance of endoscopic findings and serology in distinguishing AIG was evaluated. AIG was diagnosed in patients (N = 31) with anti-parietal cell antibody and/or intrinsic factor antibody positivity and histological findings consistent with AIG. Non-AIG patients (N = 301) were seronegative for anti-parietal cell antibodies. Receiver operating characteristic curve analysis of the entire cohort (N = 332) identified an endoscopic atrophic grade cutoff point of O3 on the Kimura–Takemoto classification (area under the curve [AUC]: 0.909), while those of pepsinogen-I, I/II ratio, and gastrin were 20.1 ng/mL (AUC: 0.932), 1.8 (AUC: 0.913), and 355 pg/mL (AUC: 0.912), respectively. In severe atrophy cases (≥ O3, N = 58, AIG/control; 27/31), the cutoff values of pepsinogen-I, I/II ratio, and gastrin were 9.8 ng/mL (AUC: 0.895), 1.8 (AUC: 0.86), and 355 pg/mL (AUC: 0.897), respectively. In conclusion, endoscopic atrophy is a predictor of AIG. High serum gastrin and low pepsinogen-I and I/II ratio are predictors even in the case of severe atrophy, suggesting their usefulness when the diagnosis of AIG is difficult or as serological screening tests.

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.

Decreased anti-parietal cell antibody titer in the advanced phase of autoimmune gastritis

BACKGROUND

Autoimmune gastritis (AIG) is histologically classified into three phases according to the severity of oxyntic mucosal atrophy: early, florid, and end phases. This study aimed to clarify the relationship between the AIG phase and the anti-parietal cell antibody titer.

METHODS

Patients who underwent upper gastrointestinal endoscopy were retrospectively reviewed in this study. We enrolled patients who were histologically diagnosed with AIG and serologically tested for anti-parietal cell antibody (APCA). AIG patients were classified into three groups: early, florid, and end phase groups. Clinical characteristics, including APCA titers, were compared among these three groups.

RESULTS

A total of 44 AIG patients were enrolled. There were two patients in the early phase, 11 in the florid phase, and 31 in the end phase. APCA-positive rates were 100% in the early phase, 90.9% in the florid phase, and 90.3% in the end phase. The mean APCA titer was 480 U in the early phase, 220 U in the florid phase, and 150 U in the end phase. There was a stepwise decrease in the APCA titer from the early phase to the end phase. The mean APCA titer for the end phase was significantly lower than that of the early phase or florid phase. Additionally, there was a stepwise decrease in serum gastrin levels from the early phase to the end phase.

CONCLUSION

AIG progresses from the early phase to the end phase, and the APCA titer shows a decrease. The negativity of APCA could occur, especially in the end phase.

The role of advanced endoscopy in the management of inflammatory digestive diseases (upper gastrointestinal tract)

The Japan Gastroenterological Endoscopy Society held four serial symposia between 2019 and 2020 on the state-of-the-art of issues related to upper GI inflammatory diseases. This review discusses some of the topics addressed in these symposia. The papers regarding nonerosive reflux disease, recent improvements in intraesophageal pH-impedance monitoring and endoscopic diagnosis using image-enhanced endoscopy have been published. Many publications have addressed its usefulness in endoscopic treatment of gastroesophageal reflux disease such as anti-reflux mucosectomy. In the management of eosinophilic esophagitis, since the symptoms are subjective, objective indicators have been sought, and ultrasonography and high-resolution manometry may be useful tools for evaluation. The natural course of this condition, especially of asymptomatic cases, is not well clarified. Some newly developed anti-acid or anti-inflammatory medicines are now under investigation. With regard to autoimmune gastritis, because of widespread medical examinations, diagnosis of asymptomatic cases has been increasing. Recently, its endoscopic characteristics have become clear and the natural history of these conditions is being elucidated. The Kyoto Classification of Gastritis has been reported to be useful not only for Helicobacter pylori diagnosis but also for identification of risks of gastric cancer. Its usefulness is now recognized in Asia and Europe.

Clue of Diagnosis for Autoimmune Gastritis

BACKGROUND

The diagnostic clues for autoimmune gastritis (AIG) can be classified into 2 categories: endoscopic findings and pathological diagnosis. We believe that research on the AIG detection rate by endoscopists could provide a better understanding of the diagnosis of AIG. This study aimed to clarify the ratio of the endoscopic and the pathological diagnoses of AIG.

METHODS

We retrospectively reviewed consecutive patients who underwent esophagogastroduodenoscopy (EGD). During their first EGD, the gastric mucosa with C2 atrophy or more was biopsied for pathological evaluation based on the updated Sydney system. A gastric biopsy was also performed after Helicobacter pylori eradication, obtaining specimens from at least 2 sites, the greater curvature of the corpus and the antrum. We enrolled patients who were positive for the anti-parietal cell antibody and were diagnosed with AIG, histologically and/or endoscopically. The detection rates of AIG were compared between endoscopic diagnosis and pathological diagnosis.

RESULTS

A total of 10,822 patients underwent EGD during the study period. Finally, 41 patients with AIG were enrolled, leading to an AIG prevalence of 0.38% in this study. As for the clue leading to AIG detection, 31.7% (13/41) were diagnosed through endoscopy (proximal-predominant atrophy), and 68.3% (28/41) were diagnosed pathologically. The AIG detection rate by endoscopists in the posteradication group was significantly lower than in the H. pylori-negative group (p < 0.05).

CONCLUSION

Endoscopists frequently overlooked AIG, especially in posteradication cases. Pathological assessment using the updated Sydney system after H. pylori eradication might be a promising strategy to detect AIG better.