Association ofHelicobacter pyloriinfection with Toll-like receptor-4 Thr399Ile polymorphism increased the risk of peptic ulcer development in North of Iran

TLR4 rs4986790 polymorphism confers risk to Helicobacter pylori infection in Zhejiang, China and its enlightenment to nursing care

PURPOSE

Previous literatures on the association between TLR4 gene rs4986790 polymorphism and Helicobacter pylori infection risk reported conflict results. We conducted a case-control study and meta-analysis to investigate whether TLR4 gene rs4986790 polymorphism confers risk to Helicobacter pylori infection.

PATIENTS AND METHODS

254 patients with Helicobacter pylori positive and 235 patients with Helicobacter pylori negative were enrolled. PubMed, Embase, CNKI (Chinese national knowledge internet) were carefully searched and reviewed. Odds ratio (OR) together with 95% confidence interval (CI) were applied to calculate the association power.

RESULTS

GG genotype of TLR4 gene rs4986790 polymorphism contributes increased risk to the population of Zhejiang, China (p = 0.019). Meta-analysis found that the positive findings came from Asian population by allele contrast (p = 0.006), homozygote comparison (p = 0.006) and recessive genetic model (p = 0.001).

CONCLUSION

TLR4 gene rs4986790 polymorphism is associated with Helicobacter pylori infection risk for population of Zhejiang, China. Combined with individual gene polymorphism, the accuracy of risk assessment of Helicobacter pylori infection can be improved and individualized health education can be provided for patients with Helicobacter pylori infection by nurses.

Association of toll-like receptor 4, 5 and 10 polymorphisms with Helicobacter pylori-positive peptic ulcer disease in a center in Jordan

BACKGROUND

Helicobacter pylori infection is widespread, affecting about 50% of the global population. Polymorphisms in host genes such as the toll-like receptor 4 (TLR4) might affect the susceptibility and severity of infection and treatment success.

OBJECTIVE

Investigate the susceptibility and severity of H pylori infection with host TLR4 (rs11536889, rs4986790, rs200109652, rs10759932), TLR5 (rs5744174, rs2072493, rs746250566), TLR10 (rs559182335, rs10004195) polymorphisms.

DESIGN

Analytical, cross-sectional.

SETTING

Endoscopy clinic at tertiary care center.

PATIENTS AND METHODS

Genomic DNA was extracted from formalin-fixed paraffin-embedded tissues collected from H pylori-infected patients and healthy individuals. The single nucleotide polymorphisms (SNPs) within the targeted TLR genes were genotyped to assess the genetic association of various SNPs with disease severity.

MAIN OUTCOME MEASURES

Effect of genotype distribution on H pylori infection.

SAMPLE SIZE

250 peptic ulcer patients and 217 controls.

RESULTS

The TLR10 genotype showed no significant association with H pylori infection except for rs10004195 (T>A) (P=.002). The genotype frequency of Rs5744174 in TLR5 had a significant association with the presence of H pylori infection (P=.046, OR=0.52). Except for gender (P=.022), there were no significant associations between clinical and demographic variables and SNPs relating to the severity of the H pylori infections.

CONCLUSIONS

Our findings are consistent with differences in severity of H pylori infection due to TLR SNPs in different ethnic groups. Understanding differences in genetic susceptibility could help in classifying patients and matching patients with various treatment options on a genetic basis.

LIMITATIONS

Lack of H pylori pathogenicity features assessment.

CONFLICTS OF INTEREST

None.

Association of toll-like receptors 2, 4, 9 and 10 genes polymorphisms and Helicobacter pylori-related gastric diseases in Saudi patients

Purpose

Helicobacter pylori is one of the most prevalent human pathogens worldwide. However, the outcomes of H. pylori infection are markedly variable from asymptomatic mild lesion to malignant transformation. Many factors are suggested to influence these infection outcomes, including host immunity and genetic susceptibility. Toll-like receptors (TLRs) can recognise different microbial components and play an essential role in the mucosal immune response against H. pylori infection.

Materials and Methods

The association between the common single nucleotide polymorphisms (SNPs) in the genes of TLR2, 4, 9 and 10 and H. pylori-related gastric diseases were investigated by molecular methods after the confirmation of H. pylori infection. The study included 210 patients in three groups; chronic gastritis (n = 90), peptic ulcer disease (PUD) (n = 75) and gastric carcinoma (n = 45).

Results

The results showed a significant association between TLR4 SNPs (rs 4986790 and rs 4986791) and the presence of H. pylori infection, especially in chronic gastritis patient group. Furthermore, TLR9-rs352140 TT genotype was more prevalent among chronic gastritis patient group. TLR10-rs 10004195 TT genotype was found to be less prevalent among H. pylori-related chronic gastritis and PUD and was suspected to have a protective effect. TLR2 SNPs (rs3804099 and rs3804100) showed no significant statistical difference between H. pylori-infected patients and the controls.

Conclusion

TLR genes polymorphisms may play a role in H. pylori infection susceptibility and may influence its outcomes; however, the ethnic and other factors may modify this effect.

The associations between Toll-like receptor 4 gene polymorphisms and hepatitis C virus infection: a systematic review and meta-analysis

Background and objective: The hepatitis C virus (HCV) is able to cause a life-threatening disease relating to lethal hepatocellular carcinoma. Previous, Toll-like receptor polymorphisms were proposed as promising biomarker for HCV-related hepatocellular carcinoma and disease progression. This study aimed to summarize the association of TLR4 polymorphisms and HCV infection through meta-analysis.

Methods: We applied a systematic review and meta-analysis performed by using PubMed, EMBASE and Web of Science searches. The Modified Newcastle-Ottawa scale was used for quality assessment. The odd-ratio (OR) and 95% confidence interval (CI) were calculated to assess the association. In silico analysis was applied for proposing the function as microRNA (miRNA) of non-coding polymorphism. Finally, the miRNA target was predicted and annotated to suggest the possible relationship between polymorphism and HCV infection.

Results: Our meta-analysis incorporated seven studies involving rs4986791, rs4986790 and rs2149356. No association exists between rs4986791 and HCV infection. However, the heterozygous model (AG vs GG) of rs4986790 significantly associates with HCV infection (OR = 0.33, 95% CI = 0.21–0.49, P<0.0001). Moreover, the rs2149356 TG genotype also associates with HCV infection in the over-dominant model (TG vs TT+TG: OR = 0.54, 95% CI = 0.40–0.75). In silico analysis of rs2149356G allele showed that this mutation is siRNA, which targets the set of genes, especially in the autophagy pathway.

Conclusion: We demonstrated that rs4986790 and rs2149356 are associated with HCV infection.

The role of T helper 1-cell response in Helicobacter pylori-infection

Helicobacter pylori (H. pylori) is a human pathogen affecting over 50% of the world population. This pathogen is usually associated with chronic inflammation of the gastric mucosa that can lead to peptic ulcer disease (PUD) and gastric cancer (GC), especially in susceptible individuals. These outcomes have been attributed to the interaction of several factors, including host genetic susceptibility, local innate and adaptive immune responses, virulence factors of H. pylori, and environmental factors. T helper (Th) cell subsets and their signature cytokines especially IFN-γ, contribute to anti-bacterial response, but at the mean time sustaining chronic inflammatory responses in the site of infection. It has been acknowledged that H. pylori-infection results in a Th1-dominant response and that inflammation of the gastric mucosa depends mainly on Th1 cell responses. But, the mechanism of the role of Th1 cell responses in H. pylori-infection has not yet been clearly explained. In this review, we will focus on the role of Th1 involved in H. pylori-infection, its interaction with Th17/Treg cells and its association with the clinical consequences of the infection.

Influence of Helicobacter pylori virulence factors CagA and VacA on pathogenesis of gastrointestinal disorders

Helicobacter Pylori (H. pylori) is a gram-negative bacteria infecting numerous people all over the world. It has been established that H. pylori play an important role in pathogenesis of gastritis, peptic ulcer and gastric cancer. Pathogenic features of this bacterium are mainly attributes to the existence of pathogenic islands (PAI) genes. The most known genes in these islands are cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene (VacA). Most studies demonstrated various frequency of CagA and VacA in patient with peptic ulcer or gastritis in different countries. This variation in CagA and VacA frequency may be due to the capability of this bacterium to be genetically versatile and can alter the expression of these genes with geographic diversity. Although H. pylori infection is not usually associated with any clinical symptoms, but sometimes leads to inflammation in gastrointestinal system and resulted in peptic ulcer and gastric cancer. In this regard, this review will illustrate the importance of Helicobacter pylori in pathogenesis of gastrointestinal disorders with focusing on CagA and VacA virulence factors.