Relationship between the cytotoxin-associated gene-A status of H pylori strains and cerebral infarction in European Caucasians and Chinese Han: A meta-analysis

Helicobacter pylori and cardiovascular risk: Only a dead Helicobacter is a good Helicobacter?

OBJECTIVES

Helicobacter pylori (H. pylori) and cardiovascular (CV) disease share common symptoms and underlie many general medical complaints. Preliminary studies suggest an association between H. pylori positivity and CV risk, and gastroenterological guidelines recommend eradication of H. pylori in patients with manifest atherosclerosis. Therefore, the aim of this study was to examine the reciprocal association of H. pylori positivity and CV risk for their independence of shared risk factors.

METHODS

We included 3284 asymptomatic participants of a colorectal cancer screening cohort who were offered and underwent upper gastrointestinal endoscopy. We calculated the 10-year risk for a CV event using the novel SCORE2 for each patient. We evaluated the association between H. pylori positivity and CV risk assessed by SCORE2 using both multilevel logistic and linear regression. We adjusted for age, sex and the concomitant diagnosis of metabolic syndrome. Lastly, we assessed the association between H. pylori status and mortality using proportional hazard Cox regression.

RESULTS

In total, 2659 patients were H. pylori negative and 625 H. pylori positive. Helicobacter pylori positivity was associated with SCORE2 and remained so (r = .33; 95% CI 0.09-0.57; p = .006) after adjustment for age, sex, and the diagnosis of metabolic syndrome. Also, SCORE2 was associated with higher odds for H. pylori positivity (aOR 1.03 95% CI 1.01-1.05; p = .02) even after multivariable adjustment. Helicobacter pylori positivity was associated with neither CV (HR 0.60 95% CI 0.14-2.63; p = .50) nor all-cause (HR 1.20 95% CI 0.77-1.87; p = .43) mortality during a median follow-up of 9 years.

CONCLUSIONS

In our study, H. pylori positivity and CV risk were independently associated. This did not translate into a dissimilar CV mortality between H. pylori positive and H. pylori negative patients. However, the overwhelming majority of our patients underwent H. pylori eradication. We, therefore, think that H. pylori eradication is at least safe from a cardiovascular perspective and warranted from gastrointestinal standpoint.

Hellenic consensus on Helicobacter pylori infection

The Hellenic Society of Gastroenterology recently organized the “Hellenic consensus on Helicobacter pylori (H. pylori) infection”. The aim of this publication is to report the guidelines in order to aid the national gastroenterology community in the management of H. pylori infection. Forty-one delegates from all Greek regions, including gastroenterologists, pathologists, clinical microbiologists, epidemiologists and basic scientists, were invited to this meeting. The participants were allocated to 1 of the 4 main topics of the meeting: i.e., H. pylori diagnosis and association with diseases; H. pylori and gastric cancer; H. pylori and extragastric associated disorders; and H. pylori treatment. The results of each subgroup were submitted to a final consensus vote that included all participants. Relevant data based on international and Greek publications were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. The cutoff level of 70% was considered as acceptance for the final statement. It is hoped that the recommendations and conclusions of this report will guide Greek doctors in their daily practice concerning the management of H. pylori infection.

Population attributable burden of Helicobacter pylori-related gastric cancer, coronary heart disease, and ischemic stroke in China

Helicobacter pylori, a risk factor of cancer and chronic diseases, remains highly prevalent in China. This review aims to systematically evaluate the H. pylori-attributable burden for gastric cancer (GC), coronary heart disease (CHD), and ischemic stroke (IS) in the Chinese population. Helicobacter pylori prevalence was updated by pooling the results reported in studies across China. The population attributable fraction (PAF) was calculated based on the H. pylori prevalence 10 years ago and relative risks of specific disease by reviewing the prospective studies published from 2000 through 2015. In China, the nationwide average prevalence of H. pylori was estimated to be 42.06 % in the general population during 2009-2013. The fixed effects pooled relative risk (RR) of 1.89 [95 % confidence interval (CI): 1.57-2.26] was obtained for gastric cancer and H. pylori infection. Helicobacter pylori infection was responsible for around 37.38 % of noncardia GC, corresponding to about 105,536 cases in 2012. As for extra-gastric disorders, H. pylori infections had higher risk of CHD (RR = 1.55, 95 % CI: 1.37-1.76) and IS (RR = 1.54, 95 % CI: 1.42-1.66). About 23.15 % of CHD and 22.29 % of IS were attributable to H. pylori infection. The estimates of H. pylori-attributable burden reveal a great potential of reducing H. pylori-related chronic disease burden by H. pylori eradication. Large prospective studies are warranted to identify which H. pylori strains, which subtypes of the disease, and which subgroups of the population have the greatest risk of relevant diseases and the effect of H. pylori eradication on the prevention of H. pylori-related diseases.

Peripheral to central: Organ interactions in stroke pathophysiology

Stroke is associated with a high risk of disability and mortality, and with the exception of recombinant tissue-type plasminogen activator for acute stroke, most treatments have proven ineffective. Clinical translation of promising experimental therapeutics is limited by inadequate stroke models and a lack of understanding of the mechanisms underlying acute stroke and how they affect outcome. Bidirectional communication between the ischemic brain and peripheral immune system modulates stroke progression and tissue repair, while epidemiological studies have provided evidence of an association between organ dysfunction and stroke risk. This crosstalk can determine the fate of stroke patients and must be taken into consideration when investigating the pathophysiological mechanisms and therapeutic options for stroke. This review summarizes the current evidence for interactions between the brain and other organs in stroke pathophysiology in basic and clinic studies, and discusses the role of these interactions in the progression and outcome of stroke and how they can direct the development of more effective treatment strategies.

The relationship between Helicobacter pylori and beta-2 microglobulin in humans

H. pylori is related to various gastrointestinal diseases. β₂ Microglobulin (β₂M) is an intrinsic element of major histocompatibility complex (MHC I). Serum β₂M level may increase in inflammatory states. The aim of current study is to evaluate the relationship between β₂M and H. pylori bearing CagA strains. Methods. H. pylori status was determined by histopathology of samples taken from stomach. CagA status and β₂M level were measured from blood samples of patients. Eradication therapy was administered to the patients with H. pylori infection. β₂ Microglobulin levels were measured before and after treatment. Results. 35 (29.2%) H. pylori(−) patients and 85 (70.8%) H. pylori (+) patients were included in the study. There were 52 (43.3%) patients with CagA negative and 33 (27.5%) patients with CagA positive H. pylori infection. The mean serum β₂M level was 1.83 mg/L in H. pylori (−) group, 1.76 mg/L in H. pylori (+) CagA (−) group, and 1.93 mg/L in H. pylori and CagA (+) group (P > 0.05). Serum β₂M levels (1.82 versus 1.64 mg/L P < 0.05) were decreased after eradication. Conclusion. H. pylori and CagA status did not affect β₂M level. Relationship between low grade systematic inflammation and H. pylori should be investigated to find out new predictors for diseases associated with inflammation.

Association between Helicobacter pylori and mortality in the NHANES III study

OBJECTIVE

Persistent colonisation by Helicobacter pylori, and especially by cagA-positive strains, has been related to several health outcomes with effects in opposite directions. Thus, it is important to evaluate its influence on total and category-specific mortality.

DESIGN

We conducted prospective cohort analyses in a nationally representative sample of 9895 participants enrolled in the National Health and Nutrition Examination Survey III to assess the association of H pylori status with all-cause and cause-specific mortality. Analyses for the association of H pylori cagA positivity with mortality were conducted in 7384 subjects with data on H pylori cagA status.

RESULTS

In older people (> 40.1 years), H pylori was not associated with all-cause mortality (HR 1.00; 95% CI 0.84 to 1.18). There was an inverse association of H pylori status with stroke mortality (HR 0.69; 95% CI 0.44 to 1.08), and the inverse association was stronger for H pylori cagA positivity, with the HR of 0.45 (95% CI 0.27 to 0.76). H pylori was also strongly positively related to gastric cancer mortality. After we adjusted p values using the Benjamini-Hochberg false discovery rate method to account for multiple comparisons, these associations remained, and H pylori status was not related to other outcomes.

CONCLUSIONS

Our findings suggest that H pylori has a mixed role in human health, but is not a major risk factor for all-cause mortality.

Extragastrointestinal manifestations of Helicobacter pylori infection: facts or myth? A critical review

Helicobacter pylori (H. pylori) infection is reported to be associated with many extragastrointestinal manifestations, such as hematological diseases [idiopathic thrombocytopenic purpura (ITP) and unexplained iron deficiency anemia (IDA)], cardiovascular diseases (ischemic heart diseases), neurological disorders (stroke, Parkinson's disease, Alzheimer's disease), obesity and skin disorders. Among these, the best evidence so far is in ITP and unexplained IDA, with high-quality studies showing the improvement of IDA and ITP after H. pylori eradication. The evidence of its association with coronary artery disease is weak and many of the results may be erroneous. The role of H. pylori infection in affecting serum leptin and ghrelin levels has attracted a lot of attention recently and available data to date have been conflicting. There have also been many uncontrolled, small sample studies suggesting an association between H. pylori infection and neurological disorders or chronic urticaria. However, more studies are required to clarify such proposed causal links.

Helicobacter pylori infection, chronic atrophic gastritis and major cardiovascular events: a population-based cohort study

OBJECTIVE

There is debate whether infection with Helicobacter (H.) pylori, the main inducer of chronic atrophic gastritis (CAG), is a risk factor for cardiovascular disease and premature mortality.

METHODS

Serological measurements of H. pylori infection and pepsinogen (PG) I and II were obtained in a population-based German cohort of 9953 older adults (50-74 years). Cox regression was employed to estimate hazard ratios (HR) and 95% confidence intervals (CI) for myocardial infarction, stroke, cardiovascular and all-cause mortality during five-year follow-up.

RESULTS

According to serology, 4977 participants (51.9%) were infected with H. pylori (2604 with cytotoxin-associated gene A (cagA) strains) and 541 (5.7%) had CAG (PGI<70 ng/mL and PGI/PGII<3). During follow-up, 540 participants died (163 from cardiovascular causes), 170 experienced a primary myocardial infarction and 241 had a stroke. Neither cytotoxin-associated gene A (cagA) negative nor cagA positive H. pylori infections were associated with an increased risk for myocardial infarction, stroke or all-cause mortality. Intriguingly, infection with cagA positive H. pylori strains was inversely associated with cardiovascular mortality (HR, 0.62; CI: 0.41-0.94). No statistically significant associations were observed for the small group of participants with CAG, but point estimates of adjusted HRs for myocardial infarction, stroke and cardiovascular mortality were all below 1 (0.71, 0.59 and 0.65, respectively).

CONCLUSIONS

Our results do not support the hypothesis that H. pylori infection or CAG are risk factors for cardiovascular disease or mortality and instead suggest an inverse relationship of cagA positive H. pylori infection with fatal cardiovascular events.

Influence of CagA-positive Helicobacter pylori strains on atherosclerotic carotid disease

Citotoxin-associated gene-A (CagA)-positive Helicobacter pylori strains have been associated with occurrence and destabilization of coronary atherosclerotic plaques. However, data on the relationship between CagA-positive H. pylori infection and carotid artery instability are lacking. Thus, the role of CagA antigen in patients with symptomatic and asymptomatic carotid atherosclerotic plaques was investigated. A total of 64 patients with advanced carotid artery stenosis, including 33 patients with symptomatic and 31 patients with asymptomatic internal carotid artery stenosis, verified by duplex ultrasound, all undergoing carotid endarterectomy, were studied. The control group consisted of 65 subjects without a history or presence of vascular diseases. Serology for H. pylori and CagA antigen was assessed in all participants. Specimens of atherosclerotic plaques obtained from all patients during carotid endarterectomy were analyzed immunohistochemically using anti-CagA monoclonal antibodies. The ultrasonographic plaque characteristics were also estimated. CagA antibody titers were significantly higher in symptomatic patients (8.8; range, 5.8-32.7) compared to asymptomatic patients (4.7; range, 2.1-8.8; P = 0.005) and the control group (5.0; range 2.2-7.9; P < 0.001). There was significant difference in echolucency (≥ 25% soft material) between the symptomatic and asymptomatic groups (P = 0.034) by ultrasonographic evaluation. Positive immunoreactivity between monoclonal CagA antibodies and antigens within atherosclerotic specimens was significantly higher among symptomatic patients compared to asymptomatic patients (97.0 vs. 74.2%; P = 0.009). H. pylori may play a role in the pathogenesis of the atherosclerotic process due to autoimmune mechanisms and even contribute to destabilization of carotid atherosclerotic plaques.

Expression and purification of 15N-labeled 2-SH2 protein domain of SHP-2 from Homo sapiens in Escherichia coli for NMR studies and applications

A method for 2-SH2 protein domain study was described as per the order of expression, purification and structural detection. The 2-SH2 protein of Homo sapiens SHP-2 was successfully expressed and purified. It could specifically bind to anti-SHP-2/SHPTP-2 antibody according to the MS and Western blot analysis. The NMR spectrum result reveals that the protein exists in a well-ordered structure. This can provide foundations to find out the reaction mechanism of the D phosphorylated-EPIYA motif accessible to 2-SH2, support the research and development of the novel detection chip as well as target inhibition medicine for the future clinical applications.