Evaluation of screening tests for autoimmune gastritis in histopathologically confirmed Japanese patients, and re-evaluation of histopathological classification

Screening for autoimmune atrophic gastritis by serum gastrin measurement in subjects with type 1 diabetes

INTRODUCTION

Despite associated risk of anemia and gastric cancer, screening for autoimmune atrophic gastritis (AAG) is underperformed in subjects with type 1 diabetes mellitus (T1DM). We measured the predictive value of serum gastrin as a biomarker of gastric atrophy in subjects with T1DM and parietal cell autoantibodies (PCA).

SUBJECTS AND METHODS

PCA measurements were retrospectively retrieved in 1,425 consecutive subjects with T1DM between 2014 and 2018. Screening for AAG was conducted in PCA+ subjects by measuring blood counts, serum ferritin, vitamin B12 and gastrin; and by performing gastroduodenal fibroscopy, with fundic biopsies for histology and Helicobacter pylori. The performance of blood biomarkers of gastric atrophy was analyzed in comparison with the histopathological gold standard.

RESULTS

PCA were found in 185/1,425 subjects (13 %). PCA positivity was associated with female sex, older age, longer T1DM duration, and co-occurrence of anti-GAD and anti-thyroperoxydase autoantibodies. Of the 185 PCA+ subjects, 122 (66 %) participated in screening. AAG was found in 69/122 (57 %) subjects and Helicobacter pylori infection in 20/122 (16 %). Compared to PCA+ subjects without gastric atrophy, those with gastric atrophy had more frequently iron deficiency (65 % vs. 18 %, P < 0.0001), and/or vitamin B12 deficiency (57 % vs. 7 %, P < 0.0001); 44/69 (64 %) presented a pre-tumoral lesion and 6 % a tumor. Using a cut-off of 1.2-fold above the upper normal limit, serum gastrin concentration displayed 91 % sensitivity and 82 % specificity at predicting gastric atrophy.

CONCLUSION

In subjects with T1DM and PCA, serum gastrin is a reliable biomarker of gastric atrophy that can be used to select subjects requiring gastroduodenal fibroscopy.

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.

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.

Serum pepsinogens can help to discriminate between H. pylori-induced and auto-immune atrophic gastritis: Results from a prospective multicenter study

BACKGROUND

Serum pepsinogen (PG) testing is recommended by the European guidelines for diagnosis of chronic atrophic gastritis (CAG). However, wide variations in diagnostic performances are observed, due to the differences in the extent of gastric atrophy, and possibly in its origin (Helicobacter pylori-, autoimmune (AIG)).

AIM

To analyze the diagnostic performances of PGs testing according to these different parameters, using enzyme-linked-immunosorbent serologic assay (ELISA) and chemiluminescent immunoassay (CLEIA).

METHODS

Serum samples from patients having undergone gastroscopy with biopsies in five French centers were collected prospectively. Sensitivity (Se), specificity (Sp), and Area Under Curve were analyzed according to the extent and origin of CAG.

RESULTS

Overall, 344 patients (156 males [45%]; mean age 58.8 [±14.2] years) were included, among whom 44 had AIG. Diagnostic performances of PG I for the detection of corpus CAG were excellent, with Se and Sp of 92.7% and 99.1% for ELISA and 90.5% and 98.2% for CLEIA, respectively. For AIG, corresponding values were 97.7% and 97.4% for ELISA, and 95.6% and 97.1% for CLEIA. In multivariate analysis, PG levels were associated with the auto-immune origin (p<0.001) but not with the extent of the atrophic gastritis.

CONCLUSIONS

Pepsinogens are highly efficient for the diagnosis of corpus-limited CAG and allow to discriminate AIG from H. pylori-induced gastritis.

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.