Helicobacter pylori: Bacterial Factors and the Role of Cytokines in the Immune Response

Can neutrophil to lymphocyte ratio be a non-invasive indicator of the presence of duodenal ulcer related Helicobacter pylori in dyspeptic patients?

Background and aims

Neutrophil to lymphocyte ratio (NLR), a novel inflammatory marker, has been shown to increase in various systemic inflammatory conditions. In this way, we want to evaluate the relationship between the presence of H. pylori, duodenal ulcer related H. pylori and NLR in dyspeptic patients.

Material and methods

The patients were divided into three groups after evaluating of the EGD and histopathology results. The groups were determined as follow; Group A: H. pylori positive and DU negative, Group B: H. pylori positive and DU positive, Group C: H. pylori negative and DU negative. Then, groups were compared with each other for demographic features, laboratory tests and NLR.

Results

There were significant differences between groups for NLR when groups compared with each other. Significantly high NLR was seen in group A (H. pylori positive, DU negative) and group B (H. pylori positive, DU positive) when compared with group C (H. pylori negative, DU negative) (respectively p < 0.042, p < 0.001). Significantly higher NLR was determined in the group B when compared with group A and group C (respectively p < 0.021, p < 0.001). The cut-off value for NLR was 2,17 with a specificity of 61% and sensitivity of 66% for group B comparing with Group C (AUC:0,66).

Conclusions

Significantly higher NLR was determined in patients with H. pylori and DU. As a result, NLR may be used as a non-invasive test for documenting the presence of H. pylori and H. pylori related DU.

Is Helicobacter pylori infection associated with osteoporosis? a systematic review and meta-analysis

INTRODUCTION

This study used systematic review and meta-analysis to evaluate the association between Helicobacter pylori infection and osteoporosis.

MATERIALS AND METHODS

PubMed, Ovid and Web of Science were searched to include observational studies published in English comparing bone mineral density changes between Helicobacter pylori-positive and -negative participants. The quality of the included literature was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). R software was used for meta-analysis, and odds ratio (OR) and 95% confidence interval (CI) were calculated to evaluate the relationship between Helicobacter pylori infection and osteoporosis.

RESULTS

Twenty-two studies involving 24,176 participants were included in the study. Our meta-analysis showed that Helicobacter pylori infection was significantly associated with the risk of osteoporosis (OR: 1.12, 95%CI: 1.03, 1.22). Participants infected with the CagA-positive Helicobacter pylori strain were more likely to develop osteoporosis (OR = 1.42, 95%CI: 1.09; 1.85).

CONCLUSION

Infection with Helicobacter pylori, particularly the CagA-positive strain, has been associated with an increased risk of osteoporosis. The bone health of Helicobacter pylori-positive patients deserves more attention.

Ginger Extract Modulates the Production of Chemokines CCL17, CCL20, CCL22, and CXCL10 and the Gene Expression of Their Receptors in Peripheral Blood Mononuclear Cells from Peptic Ulcer Patients Infected with Helicobacter pylori

Background: The imbalanced expression of chemokines plays critical role in the development of Helicobacter pylori-mediated complications. Objectives: Our aim was to determine ginger extract (GE) effects on the expression of chemokines CCL17, CCL20, CCL22, and CXCL10, as well as CCR4, CCR6, and CXCR3 receptors by peripheral blood mononuclear cells (PBMCs) from H. pylori -infected patients with peptic ulcer (PU). Methods: Peripheral blood mononuclear cells were obtained from 20 patients with H. pylori-associated PU, 20 H. pylori-infected asymptomatic subjects (HAS), and 20 non-infected healthy subjects (NHS). The PBMCs were stimulated by 10 µg/mL of H. pylori-derived crude extract (HPCE) in the presence of 0, 10, 20, and 30 µg/mL of GE. After 36 hours, the supernatant and the RNA extracted from the cells were tested for chemokine concentration and chemokine receptor expression using ELISA and real-time PCR techniques, respectively. Results: In PU patients, treating HPCE-stimulated PBMCs with 10, 20, or 30 µg/mL GE reduced the production of CXCL10 (1.47, 1.5, and 1.53 folds, respectively, P < 0.001 for all), CCL20 (1.44, 1.62, and 1.65 folds, respectively, P < 0.003), and treatment with 30 µg/mL GE increased CCL17 (1.28-fold, P < 0.001) and CCL22 (1.59-fold, P < 0.001) production compared with untreated HPCE-stimulated PBMCs. In PU patients, the HPCE-stimulated PBMCs treated with 10, 20, or 30 µg/mL GE expressed lower levels of CXCR3 (1.9, 3, and 3.5 folds, respectively, P < 0.001) and CCR6 (2.3, 2.7, and 2.8 folds, respectively, P < 0.002) while treating with 10 µg/mL GE upregulated CCR4 (1.7 fold, P = 0.003) compared with untreated HPCE-stimulated PBMCs. Conclusions: Ginger extract modulated the expression of chemokines and their receptors in the PBMCs derived from H. pylori-infected PU patients. The therapeutic potentials of ginger for treating HP-related complications need to be further explored.

Cohort study of Helicobacter pylori infection and the risk of incident osteoporosis in women

BACKGROUND AND AIM

Previous studies suggested an association between Helicobacter pylori infection and osteoporosis; however, large-scale longitudinal studies are lacking to elucidate this association.

METHODS

A cohort study of 10 482 women without osteoporosis at baseline who participated in a repeated health-screening examination including an H. pylori-specific immunoglobulin G antibody test was conducted to evaluate the association between H. pylori and osteoporosis development. Osteoporosis was diagnosed using dual-energy X-ray absorptiometry.

RESULTS

During the 77 515.3 person-years of follow-up, women with H. pylori infection had a higher rate of incident osteoporosis than those who were uninfected. In a multivariable model adjusted for age, body mass index (BMI), menopausal status, smoking status, regular exercise, comorbidities (including hypertension, diabetes mellitus, dyslipidemia, stroke, or ischemic heart disease), and concomitant medications, the hazard ratio (HR) for incident osteoporosis in women with H. pylori infection compared with that in women without infection was 1.23 (95% confidence interval [CI], 1.03-1.45). The association between H. pylori and osteopenia development was also evident. In the multivariable analysis, menopause (HR, 1.68; 95% CI, 1.31-2.16) and increasing age (HR, 1.07; 95% CI, 1.06-1.08) were identified as significant risk factors for osteoporosis, whereas higher BMI (HR, 0.84; 95% CI, 0.81-0.87) was a protective factor for the risk of osteoporosis.

CONCLUSIONS

In this cohort study, H. pylori infection was associated with an increased risk of osteoporosis, independent of risk factors and confounding factors.

Complex Interaction between Resident Microbiota and Misfolded Proteins: Role in Neuroinflammation and Neurodegeneration

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and Creutzfeldt-Jakob disease (CJD) are brain conditions affecting millions of people worldwide. These diseases are associated with the presence of amyloid-β (Aβ), alpha synuclein (α-Syn) and prion protein (PrP) depositions in the brain, respectively, which lead to synaptic disconnection and subsequent progressive neuronal death. Although considerable progress has been made in elucidating the pathogenesis of these diseases, the specific mechanisms of their origins remain largely unknown. A body of research suggests a potential association between host microbiota, neuroinflammation and dementia, either directly due to bacterial brain invasion because of barrier leakage and production of toxins and inflammation, or indirectly by modulating the immune response. In the present review, we focus on the emerging topics of neuroinflammation and the association between components of the human microbiota and the deposition of Aβ, α-Syn and PrP in the brain. Special focus is given to gut and oral bacteria and biofilms and to the potential mechanisms associating microbiome dysbiosis and toxin production with neurodegeneration. The roles of neuroinflammation, protein misfolding and cellular mediators in membrane damage and increased permeability are also discussed.

Association between Alzheimer's Disease and Oral and Gut Microbiota: Are Pore Forming Proteins the Missing Link?

Alzheimer's disease (AD) is a neurodegenerative condition affecting millions of people worldwide. It is associated with cerebral amyloid-β (Aβ) plaque deposition in the brain, synaptic disconnection, and subsequent progressive neuronal death. Although considerable progress has been made to elucidate the pathogenesis of AD, the specific causes of the disease remain highly unknown. Recent research has suggested a potential association between certain infectious diseases and dementia, either directly due to bacterial brain invasion and toxin production, or indirectly by modulating the immune response. Therefore, in the present review we focus on the emerging issues of bacterial infection and AD, including the existence of antimicrobial peptides having pore-forming properties that act in a similar way to pores formed by Aβ in a variety of cell membranes. Special focus is placed on oral bacteria and biofilms, and on the potential mechanisms associating bacterial infection and toxin production in AD. The role of bacterial outer membrane vesicles on the transport and delivery of toxins as well as porins to the brain is also discussed. Aβ has shown to possess antimicrobial activity against several bacteria, and therefore could be upregulated as a response to bacteria and bacterial toxins in the brain. Although further research is needed, we believe that the control of biofilm-mediated diseases could be an important potential prevention mechanism for AD development.

The Rome IV: Irritable bowel syndrome - A functional disorder

Functional gastrointestinal disorders are the most common disorders encountered in the clinical gastroenterology setting. Over the years the Rome process has generated consensus definitions of functional gastrointestinal disorders, and given diagnostic criteria, based on various symptom patterns, that have evolved over the years. The latest Rome IV consensus was presented in May 2016. This summary points out some of the important changes made from the Rome III 2006 consensus including evaluation of symptoms from the stand-point of basal normative values and disorders of gut-brain interaction, as well as additions of the importance of the microflora. However, we are all aware of the fact that there are limitations, and the Rome consensus does not pick up all patients with functional gastrointestinal disorders. Out of those that seek medical help for their functional gastrointestinal symptoms additional outlines of disease have to be considered and judgements made on the patients' actual symptoms, or rather presentation of their symptoms. The Rome IV consensus is a robust standard for a clinical and research approach to functional gastrointestinal disorders, but might be improved by use of exclusion criteria and additional biochemical biomarkers in order to accurately diagnose those patients who may achieve relief by an extended treatment approach in the clinical setting of gastroenterology. A biopsychosocial approach to the patient is recommended to improve compliance and optimize treatment and outcomes.

Altered cytokine expression in Helicobacter pylori infected patients with bleeding duodenal ulcer

Objective

Peptic ulcer disease is a condition in which an important role has infection with H. pylori. The most common complication of peptic ulcer is bleeding. The presence of H. pylori triggers local and systemic cytokine signaling which may affect processes such as healing, gastric or duodenal rupture, and carcinogenesis. In this study, we examined the concentrations of IL-1β, IL-6, IL-10, TNF, TGF-β and IL-17A in serum by enzyme immunoassay and their mRNA expressions in periulcer biopsies obtained from patients with bleeding peptic ulcer by means of real-time-PCR.

Results

We have shown that pro-inflammatory IL-6 and TNF concentrations in serum were significantly higher in patients who were infected with H. pylori, while the concentrations of TGF-β and IL-17A were significantly lower compared to non-infected subjects. IL-17A expression in periulcer mucosa was significantly higher in patients who were infected with H. pylori, while the expression of other cytokines, there was no significant difference compared to non-infected controls. Considering higher serum concentrations in non-infected subjects and higher IL-17A expression in mucosal tissue of infected patients, our data support the studies that found IL-17A has protective role in eradication of H. pylori infection in infected patients.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4310-4) contains supplementary material, which is available to authorized users.

HELICOBACTER PYLORI INFECTION AND IMMUNE PROFILE OF PATIENTS WITH DIFFERENT GASTRODUODENAL DISEASES

BACKGROUND

The association between infection with Helicobacter pylori and different gastroduodenal diseases is related to bacterial, host and environmental factors. Studies have demonstrated an association between the genetic diversity of H. pylori, especially in the vacA and cagA genes, and the development of digestive diseases such as peptic ulcer and gastric cancer. In addition, the nature of the host inflammatory response may explain these different manifestations of infection caused by this microorganism. In this respect, host factors that regulate the immune and inflammatory responses involving the functional interaction of H. pylori infection with different components of the immune system, particularly T cells, in gastroduodenal diseases still need further investigation.

OBJECTIVE

To characterize the immune response, including immunity induced by infection with H. pylori, especially virulent strains (vacA alleles and cagA gene), by analyzing the cytokine profile and T-cell population present in gastroduodenal diseases in a Brazilian population.

METHODS

In a prospective study, gastric biopsies were collected from 554 patients with different gastroduodenal diseases for histological analysis and for the determination of bacterial genotype and cytokine production (IL-4, IL-10, IFN-γ and IL-12) by ELISA.

RESULTS

The predominant genotype of the H. pylori strains isolated from the patients studied was s1m1cagA+, which was more common among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between the s1m1cagA+ genotype and a higher degree of inflammation, higher neutrophil activity and the development of intestinal metaplasia. The gastric concentrations of IFN-γ and IL-12 were significantly higher in patients infected with H. pylori than in uninfected individuals. Higher levels of these cytokines were detected in patients with gastric ulcer and cancer, while the levels of IL-4 and IL-10 in the gastric mucosa were lower in these patients. In addition, IFN-γ and IL-12 concentrations in gastric biopsies were higher in patients infected with the virulent s1m1cagA+ genotype. In contrast, IL-4 and IL-10 levels were higher in tissue infected with s2m2cagA in gastric biopsies.

CONCLUSION

Our study shows that the interaction between the type of infectious strain and the Th1 immune response can influence and perpetuate gastric inflammation, and thus contributes to the development of the different clinical manifestations of H. pylori infection.

HELICOBACTER PYLORI INFECTION IN PATIENTS WITH DIFFERENT GASTROINTESTINAL DISEASES FROM NORTHERN BRAZIL

BACKGROUND

The mechanisms whereby Helicobacter pylori produces different pathological manifestations in the stomach and duodenum are not fully understood. Considering the geographic diversity in the prevalence of virulence factors of this microorganism and their association with the development of different diseases, the search for pathogenicity markers such as CagA and VacA alleles by molecular techniques has intensified.

OBJECTIVES

To investigate the presence of H. pylori infection and the frequency of different genotypes of this bacterium in patients with gastrointestinal diseases from Northern Brazil, and to establish their association with the histopathological findings.

METHODS

In a prospective study, samples were collected from 554 patients with different gastrointestinal diseases (gastritis, duodenal ulcer, gastric ulcer, and gastric cancer) seen at a referral hospital attending the entire State of Pará, located in the metropolitan region of Belém. Data such as gender and age obtained with an epidemiological questionnaire were analyzed. The presence of H. pylori and the bacterial genotype were investigated by PCR. Gastric biopsies were assessed histologically.

RESULTS

The prevalence of H. pylori infection was 91%. Infection was more frequent among patients with gastric ulcer and gastric cancer. In these groups, there was a predominance of men and older patients when compared to the other two groups studied. The predominant bacterial genotype was s1m1cagA+, which was more frequent among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between s1m1cagA+ strains and a higher degree of inflammation, neutrophil activity and development of intestinal metaplasia.

CONCLUSION

The present study demonstrates a high incidence of H. pylori infection in the patients analyzed, especially among those with gastric ulcer and gastric cancer. Virulent s1m1cagA+ strains predominated and were associated with more severe lesions.

Chlamydia pneumoniae and Helicobacter pylori IgG seropositivities are not predictors of osteoporosis-associated bone loss: a prospective cohort study

The potential link between infection with Chlamydia pneumoniae or Helicobacter pylori and osteoporosis has not been investigated in population-based longitudinal studies. A total of 250 healthy postmenopausal women who participated in a prospective cohort study were evaluated for IgG antibodies directed against C. pneumoniae and H. p ylori, osteoprotegerin (OPG), the receptor activator of nuclear factor kappa B ligand (RANKL), CrossLaps, and osteocalcin. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine at baseline and at follow-up 5.8 years later. There were no significant differences in age-adjusted bone turnover markers, OPG, RANKL, the RANKL/OPG ratio, and BMD between the C. p neumoniae and H. p ylori IgG seropositive and seronegative subjects (P > 0.05). Neither C. p neumoniae nor H. p ylori IgG seropositivity was associated with age-and body mass index-adjusted BMD at the femoral neck and lumbar spine or bone loss at the 5.8-year follow-up. In logistic regression analysis, neither C. p neumoniae nor H. p ylori IgG seropositivities predicted incident lumbar or spine osteoporosis 5.8 years later. In conclusion, neither C. p neumoniae nor H. p ylori IgG seropositivity was associated with bone turnover markers, the RANKL/OPG ratio, BMD, or bone loss in postmenopausal women. In addition, chronic infection with C. p neumoniae or H. p ylori did not predict incident osteoporosis among this group of women.

Herpes Simplex Virus Type 1 and Other Pathogens are Key Causative Factors in Sporadic Alzheimer's Disease

This review focuses on research in epidemiology, neuropathology, molecular biology, and genetics regarding the hypothesis that pathogens interact with susceptibility genes and are causative in sporadic Alzheimer's disease (AD). Sporadic AD is a complex multifactorial neurodegenerative disease with evidence indicating coexisting multi-pathogen and inflammatory etiologies. There are significant associations between AD and various pathogens, including Herpes simplex virus type 1 (HSV-1), Cytomegalovirus, and other Herpesviridae, Chlamydophila pneumoniae, spirochetes, Helicobacter pylori, and various periodontal pathogens. These pathogens are able to evade destruction by the host immune system, leading to persistent infection. Bacterial and viral DNA and RNA and bacterial ligands increase the expression of pro-inflammatory molecules and activate the innate and adaptive immune systems. Evidence demonstrates that pathogens directly and indirectly induce AD pathology, including amyloid-β (Aβ) accumulation, phosphorylation of tau protein, neuronal injury, and apoptosis. Chronic brain infection with HSV-1, Chlamydophila pneumoniae, and spirochetes results in complex processes that interact to cause a vicious cycle of uncontrolled neuroinflammation and neurodegeneration. Infections such as Cytomegalovirus, Helicobacter pylori, and periodontal pathogens induce production of systemic pro-inflammatory cytokines that may cross the blood-brain barrier to promote neurodegeneration. Pathogen-induced inflammation and central nervous system accumulation of Aβ damages the blood-brain barrier, which contributes to the pathophysiology of AD. Apolipoprotein E4 (ApoE4) enhances brain infiltration by pathogens including HSV-1 and Chlamydophila pneumoniae. ApoE4 is also associated with an increased pro-inflammatory response by the immune system. Potential antimicrobial treatments for AD are discussed, including the rationale for antiviral and antibiotic clinical trials.

Is the neutrophil-to-lymphocyte ratio a potential diagnostic marker for peptic ulcer perforation? A retrospective cohort study

OBJECTIVES

Peptic ulcer perforation (PUP) accounts for 5% of all abdominal emergencies and is recognized as a gastrointestinal emergency requiring rapid and efficient clinical evaluation and treatment. The mortality rate ranges from 10% to 40% among patients with perforation. In the present retrospective study, we examined the potential utility of the neutrophil-to-lymphocyte ratio (NLR) in early diagnosis of PUP; we asked whether this ratio allowed PUP and peptic ulcer disease to be distinguished.

METHODS

We enrolled the following patients: 58 with PUP, 62 with noncomplicated peptic ulcer diseases (NCPU), and 62 controls, between May 2010 and 2015. Patients who underwent surgical repair to treat PUP were included in the study group. Another group consisted of NCPU patients who had a noncomplicated peptic ulcer. The control group consisted of patients presenting with nonspecific abdominal pain to the emergency department.

RESULTS

The mortality rate was 5.2% in the PUP group. The white blood cell count, C-reactive protein, and NLRs were higher in the PUP compared to the other groups (P<.001 for all). The white blood cell count and NLR did not differ between the NCPU and control groups. The sensitivities, specificities, positive predictive values, and negative predictive values of the NLRs were 68.0%, 88.0%, 82.9%, and 72.9%, respectively.

CONCLUSIONS

We suggest that preoperative NLR aids in the diagnosis of PUP and can be used to distinguish this condition from peptic ulcer disease. Thus, the NLR should be calculated in addition to the clinical examination.

Polymorphisms of the IL-6, IL-8 and IL-10 genes and the risk of gastric pathology in patients infected with Helicobacter pylori

BACKGROUND/PURPOSE

Helicobacter pylori-induced gastric mucosal inflammation is mediated by proinflammatory and anti-inflammatory cytokines. Polymorphisms in genes that code cytokines influence cytokine secretion levels and appear to contribute to the risk of gastric diseases. In this sense, we performed this study to identify the polymorphisms in the IL-6, IL-8, and IL-10 genes and their associations with H. pylori infection and gastric pathologies.

METHODS

Gastric biopsy samples of 151 patients infected with H. pylori and 76 uninfected individuals were used. Helicobacter pylori infection was diagnosed by histological examination and the detection of the ureA and glmM genes. The polymorphisms in the IL-6 (at position -174), IL-8 (at position -251), and IL-10 (at position -819) were detected by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Among the genetic polymorphisms studied, we observed that only the presence of the A allele at position -251 of the IL-8 gene was significantly associated with H. pylori infection. In addition, patient carriers of the A/A genotype at position -251 of the IL-8 gene and carriers of the T allele at position -819 of the IL-10 gene had an increased risk of peptic ulcer disease in the presence of H. pylori infection. We did not find a correlation between polymorphisms in the IL-6, IL-8, and IL-10 genes and a higher risk of gastric carcinoma.

CONCLUSION

We demonstrated that polymorphisms in the IL-8 gene was significantly associated with H. pylori infection. Furthermore, polymorphisms in the IL-8 and IL-10 genes were associated with an enhanced risk of peptic ulcer disease in H. pylori-positive patients.

Genetic polymorphisms and tissue expression of interleukin-22 associated with risk and therapeutic response of gastric mucosa-associated lymphoid tissue lymphoma

Chronic Helicobacter pylori-stimulated immune reactions determine the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. We aimed to explore the genetic predisposition to this lymphoma and its clinical implication. A total of 68 patients and 140 unrelated controls were genotyped for 84 single-nucleotide polymorphisms in genes encoding cytokines, chemokines and related receptors that play important roles in T cell-mediated gastrointestinal immunity. Five genotypes in IL-22, namely CC at rs1179246, CC at rs2227485, AA at rs4913428, AA at rs1026788 and TT at rs7314777, were associated with disease susceptibility. The former four genotypes resided in the same linkage disequilibrium block (r(2)=0.99) that conferred an approximately threefold higher risk. In vitro experiments demonstrated that co-culturing peripheral mononuclear cells or CD4(+) T cells with H. pylori stimulated the secretion of interleukin-22 (IL-22), and that IL-22 induced the expression of antimicrobial proteins, RegIIIα and lipocalin-2, in gastric epithelial cells. Furthermore, patients with gastric tissue expressing IL-22 were more likely to respond to H. pylori eradication (14/22 vs 4/19, P<0.006). We conclude that susceptibility of gastric MALT lymphoma is influenced by genetic polymorphisms in IL-22, the product of which is involved in mucosal immunity against H. pylori and associated with tumor response to H. pylori eradication.

A second-generation protein-protein interaction network of Helicobacter pylori

Helicobacter pylori infections cause gastric ulcers and play a major role in the development of gastric cancer. In 2001, the first protein interactome was published for this species, revealing over 1500 binary protein interactions resulting from 261 yeast two-hybrid screens. Here we roughly double the number of previously published interactions using an ORFeome-based, proteome-wide yeast two-hybrid screening strategy. We identified a total of 1515 protein-protein interactions, of which 1461 are new. The integration of all the interactions reported in H. pylori results in 3004 unique interactions that connect about 70% of its proteome. Excluding interactions of promiscuous proteins we derived from our new data a core network consisting of 908 interactions. We compared our data set to several other bacterial interactomes and experimentally benchmarked the conservation of interactions using 365 protein pairs (interologs) of E. coli of which one third turned out to be conserved in both species.

The association of interleukin-18 promoter polymorphisms and serum levels with duodenal ulcer, and their correlations with bacterial CagA and VacA virulence factors

BACKGROUND

We analyzed the impact of interleukin (IL)-18 promoter polymorphisms on IL-18 serum levels in Helicobacter pylori-infected duodenal ulcer (DU) patients and healthy asymptomatic (AS) carriers. We also aimed to determine the association of the H. pylori virulence factors CagA and VacA antibodies with serum concentrations of IL-18 in order to elucidate any correlation between them.

METHODS

Three groups of patients were enrolled: DU patients (67 individuals), AS carriers (48 individuals), and H. pylori-negative subjects (26 individuals). Serum concentrations of IL-18 were determined by ELISA. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial CagA and VacA. Genotyping of IL-18 promoter polymorphisms at positions - 137G/C and - 607C/A were performed by allele-specific primer PCR protocol.

RESULTS

Our study revealed that serum IL-18 levels are positively influenced by CagA-positive H. pylori strains, so that maximum levels of IL-18 were detected in DU patients with the CagA(+) phenotype, regardless of the presence of the anti-VacA antibody. Regarding IL-18 promoter polymorphisms, the AA genotype and A allele at position - 607C/A were found to be significantly lower in DU patients than in AS carriers and H. pylori-negative subjects (p = 0.032 and 0.043, respectively).

CONCLUSIONS

The IL-18 - 607C variant was associated with higher levels of serum IL-18 and an increased risk of DU. Moreover, our findings indicated that serum concentrations of IL-18 were influenced by CagA factor, irrespective of the VacA status, suggesting that high levels of IL-18 in CagA-positive subjects predisposes to susceptibility to DU.

The skin microbiome: current perspectives and future challenges

Complex communities of bacteria, fungi, and viruses thrive on our skin. The composition of these communities depends on skin characteristics, such as sebaceous gland concentration, moisture content, and temperature, as well as on host genetics and exogenous environmental factors. Recent metagenomic studies have uncovered a surprising diversity within these ecosystems and have fostered a new view of commensal organisms as playing a much larger role in immune modulation and epithelial health than previously expected. Understanding microbe-host interactions and discovering the factors that drive microbial colonization will help us understand the pathogenesis of skin diseases and develop new promicrobial and antimicrobial therapeutics.

Complex T cell interactions contribute to Helicobacter pylori gastritis in mice

Disease due to the gastric pathogen Helicobacter pylori varies in severity from asymptomatic to peptic ulcer disease and cancer. Accumulating evidence suggests that one source of this variation is an abnormal host response. The goal of this study was to use a mouse model of H. pylori gastritis to investigate the roles of regulatory T cells (Treg) as well as proinflammatory T cells (Th1 and Th17) in gastritis, gastric T cell engraftment, and gastric cytokine production. Our results support published data indicating that severe gastritis in T cell recipient mice is due to failure of Treg engraftment, that Treg ameliorate gastritis, and that the proinflammatory response is attributable to interactions between several cell subsets and cytokines. We confirmed that gamma interferon (IFN-γ) is essential for induction of gastritis but showed that IFN-γ-producing CD4 T cells are not necessary. Interleukin 17A (IL-17A) also contributed to gastritis, but to a lesser extent than IFN-γ. Tumor necrosis factor alpha (TNF-α) and IL-17F were also elevated in association with disease. These results indicate that while H. pylori-specific CD4(+) T cells and IFN-γ are both essential for induction of gastritis due to H. pylori, IFN-γ production by T cells is not essential. It is likely that other proinflammatory cytokines, such as IL-17F and TNF-α, shown to be elevated in this model, also contribute to the induction of disease. We suggest that gastritis due to H. pylori is associated with loss of immunoregulation and alteration of several cytokines and cell subsets and cannot be attributed to a single immune pathway.

Circulating levels of interleukin (IL)-12 and IL-13 in Helicobacter pylori-infected patients, and their associations with bacterial CagA and VacA virulence factors

OBJECTIVE

The aim of this study was to determine the association of the Helicobacter pylori virulence factors, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) antibodies, with serum levels of interleukin (IL)-12 and IL-13 in H. pylori-infected duodenal ulcer (DU) patients and H. pylori-infected asymptomatic (AS) carriers in order to elucidate any correlation between them.

METHODS

A total of 67 DU patients, 48 AS individuals, and 26 healthy H. pylori-negative subjects were enrolled in this study. Serum concentrations of IL-12 and IL-13 were determined by enzyme-linked immunosorbent assay (ELISA) method. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial virulence antigens p120 (CagA) and p95 (VacA). Serum concentrations of IL-12 and IL-13 were compared in 9 groups, including 4 AS phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), 4 DU phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), and 1 control group.

RESULTS

The results revealed that DU patients positive for CagA, independent of the anti-VacA antibody status, showed drastically elevated levels of IL-12 (251 ± 43 pg/ml) when compared with the other groups (p = 0.0001). No significant difference was found between groups regarding levels of IL-13 (p > 0.05).

CONCLUSIONS

Our findings indicate that in the DU group, the serum concentrations of IL-12 but not of IL-13 were influenced by bacterial CagA, independent of the VacA status, suggesting that high IL-12 levels may contribute to susceptibility to DU in CagA-positive individuals. These findings could possibly be considered to improve the predictive or prognostic values of inflammatory cytokines for DU, and also to design possible novel therapeutic approaches.

Probiotics-containing yogurts suppress Helicobacter pylori load and modify immune response and intestinal microbiota in the Helicobacter pylori-infected children

BACKGROUND

 The benefits of probiotics to the pediatric Helicobacter pylori infection remain uncertain. We tested whether the H. pylori-infected children have an altered gut microflora, and whether probiotics-containing yogurt can restore such change and improve their H. pylori-related immune cascades.

METHODS

We prospectively included 38 children with H. pylori infection confirmed by a positive ¹³C-urea breath test (UBT) and 38 age- and sex-matched noninfected controls. All of them have provided the serum and stool samples before and after 4-week ingestion of probiotics-containing yogurt. The serum samples were tested for the TNF-α, IL-10, IL-6, immunoglobulin (Ig) A, G, E, pepsinogens I and II levels. The stool samples were tested for the colony counts of Bifidobacterium spp. and Escherichia coli. The follow-up UBT indirectly assessed the H. pylori loads after yogurt usage.

RESULTS

 The H. pylori-infected children had lower fecal Bifidobacterium spp. count (p = .009), Bifidobacterium spp./E. coli ratio (p = .04), serum IgA titer (p = .04), and pepsinogens I/II ratio (p < .001) than in controls. In the H. pylori-infected children, 4-week yogurt ingestion reduced the IL-6 level (p < .01) and H. pylori loads (p = .046), but elevated the serum IgA and pepsinogen II levels (p < .001). Moreover, yogurt ingestion can improve the childhood fecal Bifidobacterium spp./E. coli ratio (p = .03).

CONCLUSIONS

 The H. pylori-infected children have a lower Bifidobacterium microflora in gut. The probiotics-containing yogurt can offer benefits to restore Bifidobacterium spp./E. coli ratio in children and suppress the H. pylori load with increment of serum IgA but with reduction in IL-6 in H. pylori-infected children.

Probiotic suppression of the H. pylori-induced responses by conjugated linoleic acids in a gastric epithelial cell line

Conjugated linoleic acids (CLA) produced by Lactobacillus acidophilus was reported to decrease the activation of nuclear factor-kappa B. CLA was suggested as one of the anti-inflammatory molecular mechanisms of probiotics. In the present study, the effects of CLA on H. pylori-induced multiple responses were evaluated. IL-8, TNF-α and iNOS were measured in mRNA and/or protein levels in AGS cells after pretreatment with CLA or CLA-containing conditioned medium (CM) produced by Lactobacillus acidophilus or Lactobacillus plantarum. The increased expressions of IL-8 mRNA/protein and TNF-α mRNA were significantly suppressed by pretreatment with CM or CLA. The levels of IL-8 protein and TNF-α mRNA were suppressed by CM pretreatment better than CLA. The expression of iNOS mRNA was also significantly inhibited by CM pretreatment. These results suggest that the suppression of multiple mediators by CLA-containing CM plays a key role in the anti-inflammatory and anti-carcinogenic effects of probiotics on H. pylori infection.

Circulating interleukin-27 levels in Helicobacter pylori-infected patients with gastric or duodenal ulcers, independent of the bacterial cytotoxin-associated gene A virulence factor

OBJECTIVE

The aim was to evaluate the interleukin (IL)-27 levels in Helicobacter pylori (H. pylori)-infected patients with gastric ulcer (GU) or duodenal ulcer (DU) and to determine its association with H. pylori virulence factor cytotoxin-associated gene A (CagA).

METHODS

In all, 127 H. pylori infected patients (including 96 DU patients, of whom 61 were anti-CagA(+) and 35 were anti-CagA(-)) and 31 GU patients (of whom 15 were anti-CagA(+) and 16 were anti-CagA(-)), 60 asymptomatic (AS) carriers (of whom 30 were anti-CagA(+) and 30 were anti-CagA(-)) and 30 healthy H. pylori-negative participants (as a control) were enrolled in the study. Serum concentrations of IL-27 were measured by the enzyme-linked immunosorbent assay method.

RESULTS

The mean levels of IL-27 in the GU (44.26 ± 7.12 pg/mL) and DU patients (40.84 ± 3.90 pg/mL) was significantly higher than those observed in the AS carriers (22.06 ± 1.90 pg/mL, P < 0.001) and the control group (18.12 ± 1.68 pg/mL, P < 0.001 and P < 0.002, respectively). In the GU, DU and AS groups the levels of IL-27 in anti-CagA(+) participants were not significantly differ from that in the anti-CagA(-) participants.

CONCLUSIONS

These results showed that the mean concentration of IL-27 in H. pylori-infected peptic ulcer (PU) patients was higher than in AS carriers and the healthy control group. The serum concentrations of IL-27 were not affected by the CagA factor.