Autoimmune Atrophic Gastritis: The Role of miRNA in Relation to Helicobacter Pylori Infection.

Introduction: MicroRNAs (miRNAs) have been proposed as diagnostic markers, biomarkers of neoplastic progression, and possible therapeutic targets in several immune-mediated diseases. We aimed to analyze the expression profile of selected miRNAs (miR21, miR142, miR223, miR155) in patients with autoimmune atrophic gastritis (AAG), patients with non-autoimmune multifocal atrophic gastritis (MAG), and healthy control subjects (HC). Materials and methods: A total of 103 patients with AAG were consecutively recruited for this study among those attending our gastroenterology outpatient clinic. Participating patients were divided into two groups: primary, not Helicobacter pylori (HP)-associated related AAG (n=57, P-AAG) and HP-associated AAG (n=46, HP-AAG); this subgroup included HP-positive patients, patients with previously reported HP infection, and patients harboring antral atrophy, considered as a stigma of HP infection. We also included 20 sex-age-matched MAG patients and 10 HC. Upper endoscopy with gastric biopsies were performed on each AAG and MAG patient. Circulating levels of miR21-5p, miR142-3p, miR223-3p, and miR155-5p were measured by RT-PCR in all groups. Results: MiR-21 was over-expressed in P-AAG (p=0.02), HP-AAG (p = 0.04), and MAG (p=0.03) compared with HC. By contrast, miR-142 was more expressed in HC than in HP-AAG (p=0.04) and MAG (p=0.03). MiR-155 showed no significant differences among the four subgroups, while, unexpectedly, miR-223 was overexpressed in HC compared to P-AAG (p=0.01), HP-AAG (p=0.003), and MAG (p<0.001), and was higher in P-AAG than in MAG (p=0.05). Conclusions: MiR-21 was over-expressed in patients with gastric precancerous conditions irrespective of etiology, while in the same subgroups miR-142 and miR-223 were under-expressed compared to healthy controls. Controlling miRNAs up- or downregulation could lead to a breakthrough in treating chronic autoimmune diseases and potentially interfere with the progression to cancer.

Objective Evidence of Gastro-Esophageal Reflux Disease is Rare in Patients with Autoimmune Gastritis.

BACKGROUND AND AIMS: Patients with autoimmune atrophic gastritis (AAG) often complain of acid reflux symptoms, despite the evidence of hypo-achlorhydria. Rome IV criteria are used to define functional esophageal disorders. Our aim was to characterize gastroesophageal reflux disease (GERD) phenotypes in patients with AAG. METHODS: Between 2017-2018, 172 AAG patients were evaluated at Gastro-Oncology outpatient clinic of University of Padua. Of them, 38 patients with reflux symptoms underwent high-resolution manometry (HRM) and multichannel intraluminal impedance-pH monitoring (MII-pH). Seventy-six AAG consecutive patients asymptomatic for gastroesophageal reflux were selected as age and gender matched controls. Serum biomarkers (pepsinogens, gastrin-17 and Helicobacter pylori antibodies), upper endoscopy, histology and clinical data were compared. RESULTS: Out of 38/172 (22%) AAG patients with reflux symptoms, 2/38 had a GERD diagnosis based on abnormal esophageal acid exposure and 6/38 had a major motility disorder (i.e. outflow obstruction). Among the 30/38 patients with normal endoscopic findings, 9/30 had reflux hypersensitivity, 19 functional heartburn, 1 functional globus, 1 functional chest pain according to the Rome IV criteria. Antral atrophy, advanced corpus atrophy and OLGA stage were more frequent in controls than in reflux patients (p=0.01, p=0.031, p=0.01, respectively). No differences were found for serum biomarkers and symptom presentation. Most of the patients received proton pump inhibitors (PPIs) treatment (87%), with a minority (34%) reporting clinical benefit. CONCLUSIONS: Reflux symptoms are relatively common in AAG patients, but a firm diagnosis of GERD is rare (5%), whereas most of the patients have a functional disorder. PPI treatment is mostly clinical ineffective and should not be largely indicated.

Duodenal Histological Findings and Risk of Coeliac Disease in Subjects with Autoimmune Atrophic Gastritis: A Retrospective Evaluation.

BACKGROUND AND AIM: Autoimmune atrophic gastritis (AAG) is characterized by a variable spectrum of gastric and extra-gastric symptoms and has been associated with other autoimmune diseases. It is still unknown whether AAG patients have a higher risk of coeliac disease (CeD) or of any other particular duodenal histological damage. Our study aimed at evaluating the duodenal histological findings and the risk of CeD in patients with AAG, with and without other concurrent autoimmune diseases. METHODS: We retrospectively collected all the histological findings of the adult patients undergoing upper gastrointestinal endoscopy with concurrent duodenal and gastric biopsies at our gastroenterology unit between 2015 and 2018 and who were regularly followed up at our centre. Date of endoscopy evaluation, endoscopy indication, data on previous CeD diagnosis and on other autoimmune-associated diseases, and a description of histological diagnosis were recorded. RESULTS: Of the 2,423 evaluated endoscopies, 209 patients had an AAG diagnosis (8.6%). One hundred thirty-nine patients, aged 57.4 (standard deviation 13.2) years, were regularly followed up at our centre and were included. Of them, 4 subjects had a previous diagnosis of CeD and one had CeD diagnosis at index endoscopy. Additionally, 8 patients had an isolated increase of intraepithelial lymphocytes (IELs, 6%) and 2 villous atrophy with a normal IEL count. The risk of CeD in AAG was not modulated by the presence of other concurrent autoimmune diseases. CONCLUSIONS: We support the screening of all AAG patients with CeD autoantibodies. Findings of isolated IEL or villous atrophy are not exclusively related to CeD.

Inflammatory neurodegeneration induced by lipoteichoic acid from Staphylococcus aureus is mediated by glia activation, nitrosative and oxidative stress, and caspase activation.

In this study we investigated the mechanisms of neuronal cell death induced by lipoteichoic acid (LTA) and muramyl dipeptide (MDP) from Gram-positive bacterial cell walls using primary cultures of rat cerebellum granule cells (CGCs) and rat cortical glial cells (astrocytes and microglia). LTA (+/- MDP) from Staphylococcus aureus induced a strong inflammatory response of both types of glial cells (release of interleukin-1beta, tumour necrosis factor-alpha and nitric oxide). The death of CGCs was caused by activated glia because in the absence of glia (treatment with 7.5 microm cytosine-d-arabinoside to inhibit non-neuronal cell proliferation) LTA + MDP did not cause significant cell death (less than 20%). In addition, staining with rhodamine-labelled LTA confirmed that LTA was bound only to microglia and astrocytes (not neurones). Neuronal cell death induced by LTA (+/- MDP)-activated glia was partially blocked by an inducible nitric oxide synthase inhibitor (1400 W; 100 microm), and completely blocked by a superoxide dismutase mimetic [manganese (III) tetrakis (4-benzoic acid)porphyrin chloride; 50 microm] and a peroxynitrite scavenger [5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron (III); 100 microm] suggesting that nitric oxide and peroxynitrite contributed to LTA-induced cell death. Moreover, neuronal cell death was inhibited by selective inhibitors of caspase-3 (z-DEVD-fmk; 50 microm) and caspase-8 (z-Ile-Glu(O-Me)-Thr-Asp(O-Me) fluoromethyl ketone; 50 microm) indicating that they were involved in LTA-induced neuronal cell death.