Atrophic gastritis as a cause of hyperhomocysteinaemia

Exploring the pathogenesis of chronic atrophic gastritis with atherosclerosis via microarray data analysis

Although several studies have reported a link between chronic atrophic gastritis (CAG) and atherosclerosis, the underlying mechanisms have not been elucidated. The present study aimed to investigate the molecular mechanisms common to both diseases from a bioinformatics perspective. Gene expression profiles were obtained from the Gene Expression Omnibus database. Data on atherosclerosis and CAG were downloaded from the GSE28829 and GSE60662 datasets, respectively. We identified the differentially expressed genes co-expressed in CAG and atherosclerosis before subsequent analyses. We constructed and identified the hub genes and performed functional annotation. Finally, the transcription factor (TF)-target genes regulatory network was constructed. In addition, we validated core genes and certain TFs. We identified 116 common differentially expressed genes after analyzing the 2 datasets (GSE60662 and GSE28829). Functional analysis highlighted the significant contribution of immune responses and the positive regulation of tumor necrosis factor production and T cells. In addition, phagosomes, leukocyte transendothelial migration, and cell adhesion molecules strongly correlated with both diseases. Furthermore, 16 essential hub genes were selected with cytoHubba, including PTPRC, TYROBP, ITGB2, LCP2, ITGAM, FCGR3A, CSF1R, IRF8, C1QB, TLR2, IL10RA, ITGAX, CYBB, LAPTM5, CD53, CCL4, and LY86. Finally, we searched for key gene-related TFs, especially SPI1. Our findings reveal a shared pathogenesis between CAG and atherosclerosis. Such joint pathways and hub genes provide new insights for further studies.

Helicobacter pylori and oral-gut microbiome: clinical implications

More than half of the world's population are colonized with H. pylori; however, the prevalence varies geographically with the highest incidence in Africa. H. pylori is probably a commensal organism that has been associated with the development of gastritis, ulcers, and gastric cancer. H. pylori alone is most probably not enough for the development of gastric carcinoma, but evidence for its association with the disease is high and has, therefore, been classified by the International Agency for Research on Cancer as a Class 1 carcinogen. Bacteroidetes and Fusobacteria positively coexisted during H. pylori infection along the oral-gut axis. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Therefore, therapy regimens integrated with probiotics may abolish the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. The eradication therapy not only affects gut microbiome but also affects the oral microbiome with robust predominance of harmful bacteria. However, there have been reports of a protective role of H. pylori in Barrett's esophagus, esophageal adenocarcinoma, eosinophilic esophagitis, IBD, asthma, and even multiple sclerosis. Therefore, eradication therapy should be carefully considered, and test to treat policy should be tailored to specific communities especially in highly endemic areas. Supplementation of probiotics, prebiotics, herbals, and microbial metabolites to reduce the negative effects of eradication therapy should be considered. After failure of many eradication attempts, the benefits of H. pylori eradication should be carefully balanced against the risk of adverse effects especially in the elderly, persons with frailty, and intolerance to antibiotics.

Helicobacter pylori, persistent infection burden and structural brain imaging markers

Persistent infections, whether viral, bacterial or parasitic, including Helicobacter pylori infection, have been implicated in non-communicable diseases, including dementia and other neurodegenerative diseases. In this cross-sectional study, data on 635 cognitively normal participants from the UK Biobank study (2006-21, age range: 40-70 years) were used to examine whether H. pylori seropositivity (e.g. presence of antibodies), serointensities of five H. pylori antigens and a measure of total persistent infection burden were associated with selected brain volumetric structural MRI (total, white, grey matter, frontal grey matter (left/right), white matter hyperintensity as percent intracranial volume and bi-lateral sub-cortical volumes) and diffusion-weighted MRI measures (global and tract-specific bi-lateral fractional anisotropy and mean diffusivity), after an average 9-10 years of lag time. Persistent infection burden was calculated as a cumulative score of seropositivity for over 20 different pathogens. Multivariable-adjusted linear regression analyses were conducted, whereby selected potential confounders (all measures) and intracranial volume (sub-cortical volumes) were adjusted, with stratification by Alzheimer's disease polygenic risk score tertile when exposures were H. pylori antigen serointensities. Type I error was adjusted to 0.007. We report little evidence of an association between H. pylori seropositivity and persistent infection burden with various volumetric outcomes (P > 0.007, from multivariable regression models), unlike previously reported in past research. However, H. pylori antigen serointensities, particularly immunoglobulin G against the vacuolating cytotoxin A, GroEL and outer membrane protein antigens, were associated with poorer tract-specific white matter integrity (P < 0.007), with outer membrane protein serointensity linked to worse outcomes in cognition-related tracts such as the external capsule, the anterior limb of the internal capsule and the cingulum, specifically at low Alzheimer's disease polygenic risk. Vacuolating cytotoxin A serointensity was associated with greater white matter hyperintensity volume among individuals with mid-level Alzheimer's disease polygenic risk, while among individuals with the highest Alzheimer's disease polygenic risk, the urease serointensity was consistently associated with reduced bi-lateral caudate volumes and the vacuolating cytotoxin A serointensity was linked to reduced right putamen volume (P < 0.007). Outer membrane protein and urease were associated with larger sub-cortical volumes (e.g. left putamen and right nucleus accumbens) at middle Alzheimer's disease polygenic risk levels (P < 0.007). Our results shed light on the relationship between H. pylori seropositivity, H. pylori antigen levels and persistent infection burden with brain volumetric structural measures. These data are important given the links between infectious agents and neurodegenerative diseases, including Alzheimer's disease, and can be used for the development of drugs and preventive interventions that would reduce the burden of those diseases.

The Interplay between Helicobacter pylori and Gut Microbiota in Non-Gastrointestinal Disorders: A Special Focus on Atherosclerosis

The discovery of Helicobacter pylori (H. pylori) in the early 1980s by Nobel Prize winners in medicine Robin Warren and Barry Marshall led to a revolution in physiopathology and consequently in the treatment of peptic ulcer disease. Subsequently, H. pylori has also been linked to non-gastrointestinal diseases, such as autoimmune thrombocytopenia, acne rosacea, and Raynaud's syndrome. In addition, several studies have shown an association with cardiovascular disease and atherosclerosis. Our narrative review aims to investigate the connection between H. pylori infection, gut microbiota, and extra-gastric diseases, with a particular emphasis on atherosclerosis. We conducted an extensive search on PubMed, Google Scholar, and Scopus, using the keywords "H. pylori", "dysbiosis", "microbiota", "atherosclerosis", "cardiovascular disease" in the last ten years. Atherosclerosis is a complex condition in which the arteries thicken or harden due to plaque deposits in the inner lining of an artery and is associated with several cardiovascular diseases. Recent research has highlighted the role of the microbiota in the pathogenesis of this group of diseases. H. pylori is able to both directly influence the onset of atherosclerosis and negatively modulate the microbiota. H. pylori is an important factor in promoting atherosclerosis. Progress is being made in understanding the underlying mechanisms, which could open the way to interesting new therapeutic perspectives.

Cognitive function in UK adults seropositive for Helicobacter pylori

Associated with gastritis, peptic-ulcer disease, and gastric carcinoma, Helicobacter pylori (H. pylori) also has been associated with decreased cognitive function and dementia. In this study, we used data from the UK Biobank to further examine associations between H. pylori seropositivity and serointensity and performance on several cognitive tasks in adults 40 to 70 years of age (M = 55.3, SD = 8.1). In these analyses, H. pylori seropositivity (i.e., either positive or negative for H. pylori) and serointensity (concentration of antibodies against H. pylori antigens) in adjusted models were associated with worse function on tasks of Numeric memory, Reasoning, and errors on the Pairs matching test but better function on the Tower rearrangement task. Together, these findings suggest that H. pylori seropositivity and serointensity might be associated with worse cognitive function in this age group.

Controlling the Impact of Helicobacter pylori-Related Hyperhomocysteinemia on Neurodegeneration

Helicobacter pylori infection consists a high global burden affecting more than 50% of the world’s population. It is implicated, beyond substantiated local gastric pathologies, i.e., peptic ulcers and gastric cancer, in the pathophysiology of several neurodegenerative disorders, mainly by inducing hyperhomocysteinemia-related brain cortical thinning (BCT). BCT has been advocated as a possible biomarker associated with neurodegenerative central nervous system disorders such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and/or glaucoma, termed as “ocular Alzheimer’s disease”. According to the infection hypothesis in relation to neurodegeneration, Helicobacter pylori as non-commensal gut microbiome has been advocated as trigger and/or mediator of neurodegenerative diseases, such as the development of Alzheimer’s disease. Among others, Helicobacter pylori-related inflammatory mediators, defensins, autophagy, vitamin D, dietary factors, role of probiotics, and some pathogenetic considerations including relevant involved genes are discussed within this opinion article. In conclusion, by controlling the impact of Helicobacter pylori-related hyperhomocysteinemia on neurodegenerative disorders might offer benefits, and additional research is warranted to clarify this crucial topic currently representing a major worldwide burden.

Helicobacter Pylori Infection Induces Intestinal Dysbiosis That Could Be Related to the Onset of Atherosclerosis

Cardiovascular diseases represent one of the first causes of death around the world, and atherosclerosis is one of the first steps in the development of them. Although these problems occur mainly in elderly, the incidence in younger people is being reported, and an undetermined portion of patients without the classic risk factors develop subclinical atherosclerosis at earlier stages of life. Recently, both the H. pylori infection and the intestinal microbiota have been linked to atherosclerosis. The mechanisms behind those associations are poorly understood, but some of the proposed explanations are (a) the effect of the chronic systemic inflammation induced by H. pylori, (b) a direct action over the endothelial cells by the cytotoxin associated gene A protein, and (c) alterations of the lipid metabolism and endothelial dysfunction induced by H. pylori infection. Regarding the microbiota, several studies show that induction of atherosclerosis is related to high levels of Trimethylamine N-oxide. In this review, we present the information published about the effects of H. pylori over the intestinal microbiota and their relationship with atherosclerosis and propose a hypothesis to explain the nature of these associations. If H. pylori contributes to atherosclerosis, then interventions for eradication and restoration of the gut microbiota at early stages could represent a way to prevent disease progression.

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.

Associations of atrophic gastritis and proton-pump inhibitor drug use with vitamin B-12 status, and the impact of fortified foods, in older adults

BACKGROUND

Atrophic gastritis (AG) and use of proton pump inhibitors (PPIs) result in gastric acid suppression that can impair the absorption of vitamin B-12 from foods. The crystalline vitamin B-12 form, found in fortified foods, does not require gastric acid for its absorption and could thus be beneficial for older adults with hypochlorhydria, but evidence is lacking.

OBJECTIVES

To investigate associations of AG and PPI use with vitamin B-12 status, and the potential protective role of fortified foods, in older adults.

METHODS

Eligible participants (n = 3299) not using vitamin B-12 supplements were drawn from the Trinity-Ulster and Department of Agriculture cohort, a study of noninstitutionalized adults aged ≥60 y and recruited in 2008-2012. Vitamin B-12 status was measured using 4 biomarkers, and vitamin B-12 deficiency was defined as a combined indicator value < -0.5. A pepsinogen I:II ratio <3 was considered indicative of AG.

RESULTS

AG was identified in 15% of participants and associated with significantly lower serum total vitamin B-12 (P < 0.001) and plasma holotranscobalamin (holoTC; P < 0.001), and higher prevalence of vitamin B-12 deficiency (38%), compared with PPI users (21%) and controls (without AG and nonusers of PPIs; 15%; P < 0.001). PPI drugs were used (≥6 mo) by 37% of participants and were associated with lower holoTC concentrations, but only in participants taking higher doses (≥30 mg/d). Regular, compared with nonregular, consumption of fortified foods (i.e., ≥5 and 0-4 portions/wk, respectively) was associated with higher vitamin B-12 biomarkers in all participants, but inadequate to restore normal vitamin B-12 status in those with AG.

CONCLUSIONS

Older adults who have AG and/or use higher doses of PPIs are more likely to have indicators of vitamin B-12 deficiency. Fortified foods, if consumed regularly, were associated with enhanced vitamin B-12 status, but higher levels of added vitamin B-12 than currently provided could be warranted to optimize status in people with AG.

Helicobacter pylori: Commensal, symbiont or pathogen?

This review considers the data on Helicobacter pylori (H. pylori), which have been accumulated over 40 years since its description as an etiological factor in gastrointestinal diseases. The majority of modern publications are devoted to the study of the pathogenic properties of the microorganism in the development of chronic gastritis, peptic ulcer disease, and gastric cancer, as well as methods for its eradication. However, in recent years, there have been more and more studies which have suggested that H. pylori has a beneficial, or potentially positive, effect on the human body. The authors have attempted to objectively analyze the information accumulated in the literature on H. pylori. Some studies consider it as one of the recently identified human bacterial pathogens, and special attention is paid to the evidence suggesting that it is probably part of the composition of the human microbiome as a commensal (commensal from French to English is a table companion) or even a symbiont. The presented data discussing the presence or absence of the effect of H. pylori on human health suggest that there is an apparent ambiguity of the problem. The re-assessment of the data available on H. pylori infection is important in order to answer the question of whether it is necessary to create a program of mass H. pylori eradication or to apply a more personalized approach to treating patients with H. pylori-associated gastrointestinal diseases and to perform eradication therapy.

Is there a possible relationship between gastric intestinal metaplasia and systemic arterial stiffness?

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) is closely associated with pre-neoplastic lesions such as atrophic gastritis (AG) and gastric intestinal metaplasia (GIM). The relationshionship between inflammation, hyperhomocysteinemia and arterial stiffness is of pathophysiological relevance for the development of cardiovascular disease. This study aimed to investigate the relationship between vitamin B12, folic acid, homocysteine (Hcy) and pulse wave velocity (PWV) levels in patients with GIM, AG and non-atrophic non-metaplastic chronic gastritis.

PATIENTS AND METHODS

ninety-seven patients with GIM, 67 patients with AG and 69 patients with chronic gastritis were included in the study. Glucose, creatinine, total cholesterol, triglyceride, low-density lipoprotein, cholesterol, high-density lipoprotein cholesterol, vitamin B12, folic acid and Hcy levels were measured by biochemical methods. PWV and other vascular parameters were measured using the Phsyio-port AS device.

MAIN RESULTS

PWV was higher in patients with GIM and AG than in controls (p < 0.05 and p < 0.05, respectively). Vitamin B12 levels were significantly lower in patients with GIM and AG than in controls (p < 0.01 and p < 0.01, respectively). Folic acid levels were significantly lower in patients with GIM than in controls (p < 0.05). Hcy levels were significantly higher in patients with GIM and AG than in controls (p < 0.001 and p < 0.05, respectively). A logistic regression analysis showed that GIM, AG and vitamin B12 deficiency were predictors for arterial stiffness.

CONCLUSIONS

PWV values increased in patients with GIM and AG compared to non-atrophic non-metaplastic chronic gastritis, without different conventional cardiovascular risk factors.

Association of MTHFR C677T polymorphism with severity and localization of chronic atrophic gastritis patients without Helicobacter pylori infection: a case control study

Background

Previous reports indicate that the methylenetetrahydrofolate reductase (MTHFR) 677C > T polymorphism plays a role in gastric cancer. However, whether it influences the development and progression of atrophic gastritis remains ambiguous. We aimed to determine the possible relationship between MTHFR C677T polymorphism and the severity of atrophic gastritis.

Methods

A total of 128 patients without Helicobacter pylori infection were included in the study. The severity of gastric atrophy was assessed by pathological diagnosis using OLGA and OLGIM Gastritis Staging System. MTHFR 677C > T genotyping was performed by digital fluorescence molecular hybridization. Categorical variables were analyzed by percentages using the χ² test.

Results

In this study, the TT genotype was significantly more frequent among Helicobacter pylori-negative patients aged ≤44 years (age ≤ 44 years vs. > 44 years, P = 0.039). Patients with TT genotype showed a higher ratio of incisura with atrophy or intestinal metaplasia (TT vs. CC + CT, P = 0.02). Furthermore, TT genotype was associated with more severe lesions compared with the CC + CT genotypes (TT vs. CC + CT for atrophy: P = 0.07; for intestinal metaplasia: P = 0.01; for moderate-to-severe lesions: P = 0.01). OLGA and OLGIM stages III-IV were observed more frequently in patients with TT genotype compared with CC + CT genotypes (for OLGA: P = 0.003; for OLGIM: P = 0.036).

Conclusions

The MTHFR 677C > T TT genotype showed an increased risk of moderate-to-severe lesions by OLGA and OLGIM stages, and these results indicate that MTHFR C677T polymorphism may act as a predictive marker for precancerous gastric lesions, especially in Helicobacter pylori-negative patients aged ≤44 years.

Autoimmune gastritis

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B₁₂ (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H⁺/K⁺ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Current Perspectives in Atrophic Gastritis

PURPOSE OF THE REVIEW

Atrophic gastritis is a complex syndrome with gastric atrophy as a common trait. Helicobacter pylori infection and autoimmunity are the two main contexts in which it develops. It is slightly symptomatic, affects various aspects of general health, and remains a predisposing factor for gastric cancer. This review will update current knowledge and progress on atrophic gastritis.

RECENT FINDINGS

Atrophic gastritis affects mostly adults with persistent dyspepsia, deficient anemia, autoimmunity disease, long-term proton pump inhibitor use, and a family history of gastric cancer. Gastric biopsies, expressed as Sydney system grade and OLGA/OLGIM classifications, represent the gold standard for diagnosis and cancer risk stage, respectively. Recently, electronic chromoendoscopy has allowed "targeted biopsies" of intestinal metaplasia. The associated hypochlorhydria affects the gastric microbiota composition suggesting that non-Helicobacter pylori microbiota may participate in the development of gastric cancer. Physicians should be aware of multifaceted clinical presentation of atrophic gastritis. It should be endoscopically monitored by targeted gastric biopsies. Autoimmune and Helicobacter pylori-induced atrophic gastritis are associated with different gastric microbial profiles playing different roles in gastric tumorigenesis.

A current clinical overview of atrophic gastritis

Introduction: Atrophic gastritis (AG) is a complex syndrome which arises as a consequence of H. pylori infection or in the context of gastric autoimmunity. It often deserves a benign course but may lead to potentially life-threatening complications: cancer and anemia. This review aims to address traditional and innovative knowledge on this often under-diagnosed disorder.Areas covered: This review covers clinical presentation, risk factors, diagnosis, and management of AG and provides an updated resource for clinicians to get insight into this challenging disorder. Updated literature was searched in PubMed. Manual search from reference lists of publications was performed.Expert opinion: A case-finding strategy may be beneficial in individuals with anemia, dyspepsia, autoimmune thyropaties and type 1 diabetes, and family history of gastric cancer. AG is linked to gastric cancer risk and endoscopic surveillance is indicated according to topography of gastric atrophy and risk factors. The direction for future research in AG is summarized.

Chronic atrophic gastritis: Natural history, diagnosis and therapeutic management. A position paper by the Italian Society of Hospital Gastroenterologists and Digestive Endoscopists [AIGO], the Italian Society of Digestive Endoscopy [SIED], the Italian Society of Gastroenterology [SIGE], and the Italian Society of Internal Medicine [SIMI]

Chronic atrophic gastritis (CAG) is an underdiagnosed condition characterised by translational features going beyond the strict field of gastroenterology as it may manifest itself by a variable spectrum of gastric and extra-gastric symptoms and signs. It is relatively common among older adults in different parts of the world, but large variations exist. Helicobacter pylori-related CAG [multifocal] and autoimmune CAG (corpus-restricted) are apparently two different diseases, but they display overlapping features. Patients with cobalamin and/or iron deficiency anaemia or autoimmune disorders, including autoimmune thyroiditis and type 1 diabetes mellitus, should be offered screening for CAG. Pepsinogens, gastrin-17, and anti-H. pylori antibodies serum assays seem to be reliable non-invasive screening tools for the presence of CAG, helpful to identify individuals to refer to gastroscopy with five standard gastric biopsies in order to obtain histological confirmation of diagnosis. Patients with CAG are at increased risk of developing gastric cancer, and they should be estimated with histological staging systems (OLGA or OLGIM). H. pylori eradication may be beneficial by modifying the natural history of atrophy, but not that of intestinal metaplasia. Patients with advanced stages of CAG (Stage III/IV OLGA or OLGIM) should undergo endoscopic surveillance every three years, those with autoimmune CAG every three-five years. In patients with CAG, a screening for autoimmune thyroid disease and micronutrient deficiencies, including iron and vitamin B₁₂, should be performed. The optimal treatment for dyspeptic symptoms in patients with CAG remains to be defined. Proton pump inhibitors are not indicated in hypochlorhydric CAG patients.

Determinants of diagnostic delay in autoimmune atrophic gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is characterised by a wide clinical spectrum that could delay its diagnosis.

AIMS

To quantify the diagnostic delay in patients suffering from AAG and to explore possible risk factors for longer diagnostic delay.

METHODS

Consecutive patients with AAG evaluated at our gastroenterological outpatient clinic between 2009 and 2018 were included. Diagnostic delay was estimated as the time lapse occurring between the appearance of the first likely symptoms, laboratory alterations, and other clues indicative of AAG and the final diagnosis. Patient-dependent and physician-dependent diagnostic delays were also assessed. Multivariable regression models were fitted.

RESULTS

291 patients with AAG (mean age at diagnosis 61 ± 15 years; F:M ratio = 2.3:1) were included. The median overall diagnostic delay was 14 months (interquartile range [IQR] 4-41). Factors associated with longer median overall diagnostic delay were female sex (17 months, IQR 5-48), having a previous misdiagnosis (36 months, IQR 17-125) and a history of infertility/miscarriages (33 months, IQR 8-120), whereas a higher level of education was associated with longer patient-dependent diagnostic delay (4 months, IQR 1-12). First evaluation by a gastroenterologist was associated with a median longer diagnostic delay (6 months, IQR 2-15) compared to an internist (3 months, IQR 3-31) and a haematologist (1 month, IQR 0-2). Age, socioeconomic or marital status did not affect the diagnostic delay.

CONCLUSIONS

AAG is burdened by substantial diagnostic delay, especially in female patients, and due to lack of awareness, particularly among gastroenterologists. Uncommon vitamin B12 deficiency-related manifestations are overlooked and may prolong the diagnostic delay.

Clinical manifestations of chronic atrophic gastritis

Although the actual prevalence of chronic atrophic gastritis is unknown and it is probable that this entity goes largely underdiagnosed, patients in whom diagnosis is established usually present advanced stages of disease. Destruction of parietal cells, either autoimmune-driven or as a consequence of Helicobacter pylori infection, determines reduction or abolition of acid secretion. Hypo/achloridia causes an increase in serum gastrin levels, with an increased risk of the development of neuroendocrine tumors. Microcytic, hypochromic anemia frequently precedes the development of megaloblastic, vitamin B12-associated anemia. Moreover, vitamin B12 deficiency,may cause elevation of homocysteine, with an increase in the cardiovascular risk, and may be associated with neurological manifestations, mainly characterized by spinal cord demyelination and atrophy, with ensuing sensory-motor abnormalities. Gastrointestinal manifestations seem to be associated with non-acid reflux and tend to be non-specific.

Helicobacter pylori seropositivity's association with markers of iron, 1-carbon metabolism, and antioxidant status among US adults: a structural equations modeling approach

Objectives

We tested a model in which Helicobacter pylori seropositivity (Hp_s) predicted iron status, which in turn acted as a predictor for markers of 1-C metabolism that were then allowed to predict antioxidant status.

Methods

National Health and Nutrition Examination Surveys (NHANES 1999–2000) cross-sectional data among adults aged 20–85 y were analyzed (n = 3,055). Markers of Hp_s, iron status (serum ferritin and transferrin saturation (TS)); 1-C metabolism (serum folate (FOL_serum), B-12, total homocysteine (tHcy), methylmalonic acid (MMA)) and antioxidant status (vitamins A and E) were entered into a structural equations model (SEM).

Results

Predictors of Hp_s included older age, lower education and income, racial/ethnic groups (lowest among Non-Hispanic Whites), and lifetime cigarette smoking. SEM modeling indicated that Hp_s had a direct inverse relationship with iron status (combining serum ferritin and TS) which in turn was positively related to 1-C metabolites (higher serum folate, B-12 or lower tHcy/MMA) that were positively associated with antioxidant status (combining serum vitamins A and E). Another pathway that was found bypassed 1-C metabolites (Hps → Iron_st → Antiox). The sum of all indirect effects from Hp_s combining both pathways and the other indirect pathways in the model (Hps → Iron_st → OneCarbon; Hps →OneCarbon →Antiox) was estimated at β = -0.006±0.003, p<0.05.

Conclusions

In sum, of the total effect of H. pylori seropositivity on antioxidant status, two significant indirect pathways through Iron status and 1-Carbon metabolites were found. Randomized controlled trials should be conducted to uncover the concomitant causal effect of H. pylori eradication on improving iron status, folate, B-12 and antioxidant status among H. pylori seropositive individuals.

Role of Helicobacter pylori infection in pathogenesis of atherosclerosis

Though a century old hypothesis, infection as a cause for atherosclerosis is still a debatable issue. Epidemiological and clinical studies had shown a possible association but inhomogeneity in the study population and study methods along with potential confounders have yielded conflicting results. Infection triggers a chronic inflammatory state which along with other mechanisms such as dyslipidemia, hyper-homocysteinemia, hypercoagulability, impaired glucose metabolism and endothelial dysfunction, contribute in pathogenesis of atherosclerosis. Studies have shown a positive relations between Cytotoxic associated gene-A positive strains of Helicobacter pylori and vascular diseases such as coronary artery disease and stroke. Infection mediated genetic modulation is a new emerging theory in this regard. Further large scale studies on infection and atherosclerosis focusing on multiple pathogenetic mechanisms may help in refining our knowledge in this aspect.

Helicobacter pylori filtrate impairs spatial learning and memory in rats and increases β-amyloid by enhancing expression of presenilin-2

Helicobacter pylori (H. pylori) infection is related with a high risk of Alzheimer's disease (AD), but the intrinsic link between H. pylori infection and AD development is still missing. In the present study, we explored the effect of H. pylori infection on cognitive function and β-amyloid production in rats. We found that intraperitoneal injection of H. pylori filtrate induced spatial learning and memory deficit in rats with a simultaneous retarded dendritic spine maturation in hippocampus. Injection of H. pylori filtrate significantly increased Aβ₄₂ both in the hippocampus and cortex, together with an increased level of presenilin-2 (PS-2), one key component of γ-secretase involved in Aβ production. Incubation of H. pylori filtrate with N2a cells which over-express amyloid precursor protein (APP) also resulted in increased PS-2 expression and Aβ₄₂ overproduction. Injection of Escherichia coli (E.coli) filtrate, another common intestinal bacterium, had no effect on cognitive function in rats and Aβ production in rats and cells. These data suggest a specific effect of H. pylori on cognition and Aβ production. We conclude that soluble surface fractions of H. pylori may promote Aβ₄₂ formation by enhancing the activity of γ-secretase, thus induce cognitive impairment through interrupting the synaptic function.

Helicobacter pylori seropositivity and cognitive performance among US adults: evidence from a large national survey

BACKGROUND

Helicobacter pylori seropositivity is a potential risk for poor cognition among US adults.

METHODS

Cross-sectional data from the National Health and Nutrition Examination Survey III, Phase 1 (1988-1991), were used. Measures included age group-specific neuropsychological test batteries and two measures of H. pylori seropositivity (immunoglobulin G [IgG] and IgG CagA) (20-59 years old: n = 2090-2,248; 60-90 years old: n = 2123-2388). We explored sex- and race-specific associations.

RESULTS

Using multiple ordinary least square and zero-inflated Poisson regression models, we detected a poorer performance among those 60-90 years old with H. pylori IgG+ versus IgG- on a verbal memory test (story recall, correct items), overall (β = -0.04 [0.01], p = .010). Non-Hispanic (NH) blacks and women (20-59 years old) performed worse on the serial digits learning total errors (SDL-TE) when H. pylori IgG+ (versus IgG-), another verbal memory test (β = +0.94 [0.40; p = .029] and β = +1.19 [0.44; p = .012], respectively; p<.10 for interaction by sex and race). More trials to completion on this test (SDL-TTC) were also required among H. pylori IgG+ overall (20-59 years old; β = +0.30 [0.13], p = .033). Other race-specific associations without significant interaction by race were detected in the same direction of worse performance with seropositivity in all three major race groups and for both age categories, covering several domains of cognition.

CONCLUSIONS

H. pylori seropositivity markers were associated with poor cognition among US adults. Longitudinal research is needed to extrapolote those findings to cognitive decline, incident dementia, and Alzheimer's disease.

Homocysteine levels in chronic gastritis and other conditions: relations to incident cardiovascular disease and dementia

BACKGROUND

Homocysteine levels in circulation are determined by several factors and hyperhomocysteinemia is reportedly associated with cardiovascular diseases and dementia. The aim of this study is to determine the relation of chronic gastritis and other conditions to homocysteine levels and their relation to incident cardiovascular diseases and dementia.

METHODS

An adult population-based cohort (N = 488) was screened for H. pylori infection, gastro-duodenitis (endoscopic biopsies), disease history, and lifestyle factors. Blood samples were analyzed for pepsinogen I and II (gastric function), vitamin B12, folate, homocysteine, and cystatin C (renal function). The methylenetetrahydrofolate reductase C677T polymorphism reportedly associated with hyperhomocysteinemia was analyzed by pyrosequencing. Incident cardiovascular diseases and dementia were monitored during a median follow-up interval of 10 years.

RESULTS

At baseline, there was a positive relation of S-homocysteine to male gender, age, S-cystatin C, methylenetetrahydrofolate reductase 677TT genotype and atrophic gastritis. During follow-up, cardiovascular diseases occurred in 101/438 and dementia in 25/488 participants, respectively. Logistic regression analysis (adjusting for gender, age at baseline, follow-up interval, BMI, smoking, alcohol consumption, NSAID use, P-cholesterol, and P-triglycerides) showed an association of S-homocysteine higher than 14.5 mumol/l to cardiovascular diseases (OR 2.05 [95% c.i. 1.14-3.70]), but not to dementia overall.

CONCLUSIONS

Gender, age, vitamin B12, folate, renal function, atrophic gastritis and the methylenetetrahydrofolate 677TT genotype were significant determinants of homocysteine levels, which were positively related to incident cardiovascular diseases.

Serum biomarkers for atrophic gastritis and antibodies against Helicobacter pylori in the elderly: Implications for vitamin B12, folic acid and iron status and response to oral vitamin therapy

OBJECTIVES

To investigate the prevalence of serological markers for chronic atrophic gastritis (AG) and Helicobacter pylori antibodies (HPAb) in an elderly population, and to examine the interrelationship and significance for cobalamin, folic acid and iron status and response to oral vitamin therapy.

MATERIAL AND METHODS

The study included community-dwelling subjects (n=209), mean age 76 years, randomized to 4 month of oral daily treatment with 0.5 mg cyanocobalamin, 0.8 mg folic acid and 3 mg vitamin B(6) or placebo (double-blind). Biochemical tests were carried out before and after treatment.

RESULTS

AG, as indicated by a pepsinogen I/II ratio <2.9, occurred in 14% (26/190) and HPAb in 54% (102/190) of the subjects. AG subjects had higher levels of serum methylmalonic acid (MMA) (p<0.001), plasma homocysteine (tHcy) (p<0.05), lower haemoglobin (Hb) (p<0.01) and a higher prevalence of vitamin B(12) deficiency (p<0.01). HPAb was associated with AG, whereas AG subjects without HPAb had higher tHcy and MMA levels. There was no correlation between AG and iron status. Oral vitamin treatment led to greater (albeit non-significant) improvements in MMA, tHcy and total cobalamins in AG subjects compared to non-AG subjects.

CONCLUSIONS

AG is a common condition and is a significant determinant of vitamin B(12) status. AG is correlated to HPAB and lower Hb. Elderly AG subjects respond at least as well as non-AG subjects to oral treatment with B-vitamins in the doses employed.

High prevalence of Cag-A positive H. pylori strains in ischemic stroke: a primary care multicenter study

BACKGROUND

Previous studies suggested an association between CagA-positive H. pylori strains and ischemic stroke. The aim of the present study was to assess the prevalence of Helicobacter pylori infection and CagA status in patients with atherosclerotic stroke in the primary care setting.

MATERIALS AND METHODS

A total of 106 consecutive patients (age 76.6 +/- 8 years; males 52%) with well-documented history of atherosclerotic stroke and 106 sex-age- (age 76.5 +/- 9 years; males 52%) and social background-matched controls without relevant vascular diseases. Risk factors for ischemic stroke were recorded in all subjects. H. pylori infection was assessed by[13]C-urea breath test. A serologic assay for specific IgG against CagA was performed in infected subjects.

RESULTS

A trend toward a higher prevalence of H. pylori was observed in cases (63%) with respect to controls (54%) without reaching a statistical significance. CagA positivity was associated to a higher risk of atherosclerotic stroke (adjusted odds ratio 2.69, 95% confidence interval 1.37-5.30).

CONCLUSIONS

Our findings suggest that CagA-positive strains of H. pylori are significantly associated to atherosclerotic stroke. This is not a merely confirmative study since it has been performed for the first time in the primary care setting and included only subjects with an active infection.

Association between Helicobacter pylori-infection, C-reactive protein and status of B vitamins

PURPOSE

Some investigations, but not all, found that a chronic infection with Helicobacter pylori (Hp) is associated with deficiencies in B vitamins, elevated plasma total homocysteine concentrations (tHcy) and increased plasma levels of proinflammatory acute-phase proteins. It has been suggested that these factors promote atherogenesis and therefore could mechanistically explain why people infected with Hp might have an increased risk for cardiovascular diseases (CVD). Therefore we evaluated the association between Hp-infection, concentration of C-reactive protein (CRP), and status of various B vitamins in apparently healthy subjects.

MATERIAL AND METHODS

In 69 subjects with proved Hp-infection and 21 healthy control subjects identified in a cross sectional study, blood samples were collected to determine serum folate, serum vitamin B12, serum methylmalonic acid (MMA), serum CRP and plasma vitamin B6 and plasma total homocysteine (tHcy).

RESULTS

The mean concentration of CRP was significantly higher in the Hp-positive collective than in controls. Although mean concentrations of vitamin B12, B6, and MMA differed between the groups, statistical significance was missed. However, the mean concentrations of homocysteine and folic acid were nearly the same in both groups. In univariate analysis a significant impact of Hp-status was shown on cobalamin (p=0.028; eta square: 0.055), and in multivariate analysis of variance the Hp-status had an impact on vitamin B12-values (p=0.028; eta square 0.057).

CONCLUSIONS

In this study Hp-infection shows no significant impact on status of B vitamins, but has a significant influence on CRP concentration. However, this study does not support the hypothesis that Hp-infection is related to CVD via elevated levels of tHcy.

Current management of Helicobacter pylori infections in the elderly

Helicobacter pylori infection is a chronic gastric gram-negative infection that increases with age worldwide. However, the percentage age of H. pylori-positive elderly patients who are tested and treated for their infection remains very low. It is now demonstrated that H. pylori infection induces a whole cascade of events leading to gastric pathologies, such as peptic ulcer diseases, gastric precancerous lesions and gastric cancer. Recent data also demonstrated that H. pylori chronic infection can play a role in gastric aging, appetite regulation and extradigestive diseases, such as Alzheimer's disease, in the elderly. The diagnosis of H. pylori infection remains difficult to realize in the very old population, and the urea breath test obtains the best performance in this population. 1-week proton pump inhibitor-based triple therapy regimens are highly effective and well tolerated in elderly patients, and antibiotic resistance remains very low. Low compliance is the main factor related to treatment failure in this population.

Association between Helicobacter pylori infection and mild cognitive impairment

The association of Helicobacter pylori infection and Alzheimer's disease (AD) has recently been addressed, but no relative data exist regarding mild cognitive impairment (MCI), a prodromal phase of AD. The aim of this prospective study was to evaluate H. pylori infection, by histology in a Greek MCI cohort. Sixty-three consecutive patients with amnestic MCI and 35 normal controls underwent upper gastrointestinal endoscopy, histologic and serological examinations. The prevalence of H. pylori infection was 88.9% (56/63) in MCI patients and 48.6% (17/35) in anaemic controls, as confirmed by biopsy (P < 0.001, odds ratio: 8.47, 95% CI: 3.03-23.67). Mean serum anti-H. pylori IgG concentration and plasma total homocysteine (Hcy) titre were higher in MCI patients than controls (74.86 +/- 57.22 vs. 17.37 +/- 9.30 U/ml; and 16.03 +/- 4.28 vs. 13.5 +/- 1.20 micromol/l; P < 0.001 and P = 0.015, respectively). When compared with the anaemic participants, MCI patients exhibited more often multifocal (body and antral) gastritis (92.1% vs. 68.6%; P = 0.03); in H. pylori positive MCI patients cognitive state correlated with serum anti-H. pylori IgG concentration. In conclusion, H. pylori prevalence was significantly higher in MCI patients than controls. This infection might contribute, at least in part, to the pathophysiology of MCI, possibly through induction of chronic atrophic gastritis and elevated Hcy consequences.

No associations of Helicobacter pylori infection and gastric atrophy with plasma total homocysteine in Japanese

Recent studies have suggested that Helicobacter pylori (H. pylori) infection might be a risk factor for atherosclerosis. Since the bacterium has not been isolated from atherosclerotic lesions, a direct role in atherogenesis is not plausible. We examined associations of plasma total homocysteine (tHcy) and serum folate, independent risk factors for atherosclerosis, with H. pylori infection and subsequent gastric atrophy among 174 patients (78 males and 96 females) aged 20 to 73 years, who visited an H. pylori eradication clinic of Nagoya University from July 2004 to October 2005. Polymorphism genotyping was conducted for methylenetetrahydrofolate reductase (MTHFR) C677T and thymidylate synthase (TS) 28-bp tandem repeats by PCR with confronting two-pair primers and PCR, respectively. H. pylori infection and gastric atrophy were not significantly associated with hyperhomocysteinemia (tHcy > or = 12 nmol/ml), when adjusted by sex, age, smoking, alcohol, and genotypes of MTHFR and TS. The adjusted odds ratio of gastric atrophy for low folate level (< or = 4 mg/ml) was 0.21 (95% confidence interval = 0.05-0.78). The associations of tHcy with serum folate and MTHFR genotype were clearly observed in this dataset. The present study demonstrated that folate and MTHFR genotype were the deterministic factors of plasma tHcy, but not H. pylori infection and subsequent gastric atrophy, indicating that even if H. pylori infection influences the risk of atherosclerosis, the influence may not be through the elevation of homocysteine.

Alzheimer's disease and Helicobacter pylori infection: Defective immune regulation and apoptosis as proposed common links

Although degenerative diseases of the central nervous system, including Alzheimer's disease (AD), have an increasingly high impact on aged population their association with Helicobacter pylori (H. pylori) infection has not as yet been thoroughly researched. Current H. pylori infection appears to induce irregular humoral and cellular immune responses that, owing to the sharing of homologous epitopes (molecular mimicry), cross-react with components of nerves, thereby contributing and possibly perpetuating the apoptotic neural tissue damage observed in neurodegenerative diseases including AD. An association between AD and H. pylori infection has been recently addressed by two studies. A higher seropositivity for anti-H. pylori immunoglobulin G antibodies in 30 patients with AD than in 30 age-matched controls was reported in one study; this serological test, however, has limitations because it does not discriminate between current and old infections. In the other study, by introducing the histological method (the actual gold standard) for diagnosis of H. pylori infection, we reported a higher prevalence of H. pylori infection in 50 AD patients than in 30 anemic controls. This pathogen may influence the pathophysiology of AD by promoting platelet and platelet-leukocyte aggregation; releasing various pro-inflammatory and vasoactive substances; developing cross-mimicry with host antigens; producing reactive oxygen metabolites and circulating lipid peroxides; influencing the apoptotic process; and increasing, through induction of atrophic gastritis, homocysteine, which contributes to vascular disorders implicated in endothelial damage and neurodegeneration.

Is B vitamins deficiency associated with prevalence of Alzheimer's disease in Cuban elderly?

Alzheimer's disease (AD), is a major public health problem among the elderly in industrialized countries and a growing problem in developing countries. In Cuba, 14,6% of the population is older than 60 years. The AD prevalence in Cuba lies between 5,13-7,14%. Several studies have shown the relationship between the low nutritional status of B vitamins, hyperhomocysteinaemia with loss of neuro-cognitive function and AD. In studies during the epidemic neuropathy that affected Cuba between 1992-1993, B vitamins deficiency and smoking habits were strongly associated with the epidemic. Some studies in healthy adults and elderly after this epidemic have shown a sub-clinical deficiency of some B vitamins and a high prevalence of infection by Helicobacter pylori. The possibility that B vitamin deficiencies could be an additional risk factor for the high prevalence of the AD in Cuba is discussed.

Is there a possible relation between atrophic gastritis and premature atherosclerosis?

BACKGROUND

In this study, we have aimed to show the possible relation between atrophic gastritis and premature atherosclerosis via hyperhomocysteinemia.

MATERIALS AND METHODS

Thirty-four patients with atrophic gastritis were enrolled to the study. The control group consisted of 35 patients with non-atrophic gastritis. Classical cardiovascular disease risk factors did not significantly differ between atrophic gastritis and control subjects. The presence and degree of atrophic gastritis were assessed histologically and Helicobacter pylori infection was determined by both histologic and serologic methods. Body mass index was measured by standard technique blood fasting glucose, serum creatinine, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, vitamin B12, folic acid, and homocysteine levels were measured by biochemical methods. Carotid intima-media thickness was measured by B-mode ultrasonography to examine the premature atherosclerosis.

RESULTS

Plasma vitamin B12 levels were significantly lower (p = .00) and homocysteine levels were significantly higher (p = .01) in the atrophic gastritis group. There was no statistically significant difference in plasma folic acid levels between the two groups (p = .728). Carotid intima-media thickness was higher in the atrophic gastritis group than in the control group (0.516 mm versus 0.465 mm), but this difference did not show any statistical significance (p = .062).

CONCLUSION

Our results showed that atrophic gastritis may cause hyperhomocysteinemia, which is an independent risk factor for atherosclerosis and cardiovascular diseases. However, when compared with controls, carotid intima-media thickness of the atrophic gastritis patients was found to be higher but did not reach statistically significant levels.

Helicobacter pylori and extragastric diseases--other Helicobacters

Reports on Helicobacter pylori and extragastric diseases have almost doubled this year compared with last year, bearing witness to the persistent scientific interest in this branch of Helicobacter-related pathology. Data belong increasingly to the area of vascular medicine, as well as hematology, dermatology, pediatrics and other fields. Unfortunately, these studies show overall controversial results, due to the impact of several confounding factors, and to the difficulty of recruiting homogeneous patient populations. Furthermore, many studies continue to be conducted on Helicobacter species other than H. pylori, focusing on animal models of gastroenterological illnesses which may retain strong similarities with human diseases. In this paper, taxonomy, detection and characterisation of Helicobacter spp. will be reviewed, together with the most important data issued this year on other Helicobacters and animal models.