[Helicobacter pylori and immunogenetic factors of the host: relevance of the HLADQA1 *0102 and *0301 alleles in peptic ulcer]

Polymorphisms in HLA-DQ genes, together with age, sex, and Helicobacter pylori infection, as potential biomarkers for the early diagnosis of gastric cancer

BACKGROUND

Polymorphisms in inflammation-related genes are factors associated with the development of gastroduodenal diseases in Helicobacter pylori-infected individuals.

MATERIALS AND METHODS

We aimed to analyze polymorphisms in HLA-DQ, together with other host and H. pylori variables as risk factors for precancerous and cancerous gastric lesions. 1052 individuals were studied, including nonatrophic gastritis (NAG), intestinal metaplasia (IM), gastric cancer (GC) or duodenal ulcer (DU) patients, and healthy volunteers.

RESULTS

Patients with alleles DQA*01:01 (OR 0.78), *01:02 (OR 0.29), *01:03 (OR 0.31), and DQB*02:01/02 (OR 0.40) showed a reduced risk for GC. A multivariate logistic regression analyses showed that patients with homozygote genotypes DQA1*03:01 (OR 7.27) and DQA1*04:01 (OR 8.99) and DQB1*05:01:01 (OR 12.04) were at significantly increased risk for GC. Multivariate analyses also demonstrated that age (OR>10.0) and gender (OR>2.0) were variables that influenced significantly the risk for GC, while H. pylori infection (OR>2.5) increased the risk for IM.

CONCLUSIONS

We identified HLA-DQ alleles associated with IM and GC, and confirm that age, sex, and H. pylori infection are variables that also influence the risk for disease. The use of multiple markers, HLA-DQ alleles, age, sex, and H. pylori infection may be useful biomarkers for the early diagnosis of patients with IM and GC.

Different Pathophysiology of Gastritis in East and West? A Western Perspective

Background

Gastritis results from multifactorial gastric mucosal injury. Helicobacter pylori (Hp) is the main cause, and associated diseases have typical underlying patterns of gastritis. Gastric ulcer and gastric cancer (GC) develop from chronic atrophic corpus gastritis (CAG) which therefore represents the most important pattern. GC incidences in East Asia are substantially higher than elsewhere, and this should be also reflected by higher prevalences of CAG and characteristic differences in pathophysiology compared to the West.

Summary

The few available comparative studies of gastritis in Eastern and Western patients are summarized. The main pathogenic factors of gastritis are discussed together with their limitations to explain local differences in disease outcome. Emphasis was put to also include less well-established pathogenic host and environmental factors of possible impact.

Conclusions

CAG is more prevalent in East Asian areas with high GC incidences than the West. Geographic heterogeneity of associated diseases is due to differences in Hp prevalence and virulence as well as modulating host and environmental factors. The following may contribute to the higher burden of CAG in the East: ABD type of CagA with vacA s1 and babA2 alleles of Hp, host Lewis(b) expression in sej/sej nonsecretors, H. heilmannii, low parietal cell mass, high sodium and nitrate intake, preferences in vegetable and fruit consumption, cigarette smoking, air pollution, alcohol. Conversely, green tea, nonfermented soy products and rice may confer protective effects. Hp is on the decline, but also in a world cleared from this bacterium, differences in host genetics will continue to modify gastric disease outcome together with maintained customs as part of cultural diversity.

Association between HLA-Ⅱgene polymorphism and Helicobacter pylori infection in Asian and European population: A meta-analysis

BACKGROUND

It is generally considered that HLA-Ⅱ genes contribute to the Helicobacter pylori (Hp) infection and disease development process.

AIMS

To perform a meta-analysis to explore the relationship between HLA-Ⅱgene polymorphism and host susceptibility to Hp infection.

METHODS

Relevant cohort studies, case-control studies and cross-sectional studies were identified by searching Cochrane Library, PubMed, EMBASE, Web of Science and CBM up to July 2014. The data were extracted and methodological quality of the studies were evaluated. RevMan5.0 software was used to perform statistical analysis.

RESULTS

In Asian population, HLA-DQB1*0303 acted as the protective gene in Hp infection (statistically significant pooled OR = 0.54) and the susceptible genes in Hp infection involved HLA-DQB1*0401, HLA-DQA1*0103 and HLA-DQA1*0301 (statistically significant pooled OR and 95%CI were 3.34(1.93,5.77), 1.64(1.16,2.33) and 2.03(1.20,3.44) respectively). No statistically significant difference between DQB1*0303, HLA-DQA1*0103 and DQA1*0301 and Hp infection in European population (P>0.05). And no statistically significant difference (P>0.05) in the overall effect of the association between the rest of HLA-Ⅱalleles and Hp infection.

CONCLUSIONS

In Asian population, the protective gene HLA-DQB1*0303 and the susceptible genes HLA-DQB1*0401, HLA-DQA1*0103 and HLA-DQA1*0301 in Hp infection were established by meta-analysis. And there was no HLA-Ⅱallele was found to associate with Hp infection among European population.

Seroprevalence of Helicobacter pylori in Central-European uraemic patients and its possible association with presence of HLA-DR12 allele

OBJECTIVES

Renal disease at any stage is often accompanied by significant gastrointestinal symptoms, and Helicobacter pylori (H. pylori) is closely related to these disorders. A debate is still ongoing on the clinical significance of coexisting uraemia and H. pylori. HLA-class II genes have been repeatedly investigated for predisposition to H. pylori infection. The aim of our work was to evaluate the infection rate among uraemic patients, and study the relationship between HLA antigens and H. pylori serologic status in the same cohort.

MATERIALS AND METHODS

Data of 709 uraemic patients were collected and analyzed from 2001-2006. 58.7% of patients were male, 41.3% were female, mean age was 45.1 years (SD: +/-14.65). Microlymphocytotoxicity assay was used for typing of HLA class I, PCR-SSP for typing HLA class II alleles and enzyme immunofluorescency for specific H. pylori IgG.

RESULTS

Of 709 patients, 49.37% were seropositive for H. pylori. Age of H. pylori positive patients was 48.9 versus 41 years of negatives (P<0.0001). Prevalence of H. pylori decreased strongly with year of birth. Significant difference was observed in the occurrence of HLA-DR12 according to H. pylori serology. Of patients carrying DR12, 27 (73%) were H. pylori positive and 10 (27%) were negative [P=0.0037; risk ratios (RR): 2.76].

CONCLUSION

H. pylori infection rate and its decrease with year of birth was the same in the uraemic patients and in the normal population, according to specific prevalence figures. Frequency of HLA-DR12 was the same as in the general population; consequently, it might be a possible risk factor for H. pylori seropositivity, at least in a Central-European population.

TGFB1 gene polymorphisms: their relevance in the susceptibility to Helicobacter pylori-related diseases

Recent studies have revealed elevated expression of transforming growth factor beta1 (TGF-beta1) in gastric mucosa of patients with gastric cancer (GC) and those undergoing ulcer repair. As production of TGF-beta1 is genetically regulated, we aimed to assess whether functional polymorphisms of the TGFB1 gene are involved in susceptibility to and clinical characteristics of Helicobacter pylori-related diseases. DNA from 142 unrelated Spanish patients with GC, 200 with peptic ulcer and 342 healthy controls was typed for the MspA1I T+869C, and the Sau96I G+915C polymorphisms of the TGFB1 gene using polymerase chain reaction and RFLP analysis. H. pylori infection and CagA/VacA antibody status were determined by Western blot in patients and controls. H. pylori infection (odds ratio (OR): 11.44; 95% confidence interval (CI): 4.45-29.42; P<0.001) and non-steroidal anti-inflammatory drugs (OR: 5.07; 95% CI: 2.53-10.16; P<0.001) were identified as independent risks factors for duodenal ulcer (DU), whereas the TGFB1+869(*)C/C genotype was associated with reduced risk of developing the disease (OR: 0.32; 95% CI=0.15-0.68; P=0.003). Our results show that the TGFB1 T+869C gene polymorphism is involved in the susceptibility to DU and provide further evidence that host genetic factors play a key role in the pathogenesis of H. pylori-related diseases.

Association of Helicobacter pylori-related distal gastric cancer with the HLA class II gene DQB10602 and cagA strains in a southern European population

BACKGROUND

Distinct human leukocyte antigen (HLA)-DQ genes have been associated with an increased or reduced risk for gastric cancer, but its association with Helicobacter pylori status is controversial. In the present study we evaluated the influence of host HLA DQA1 and DQB1 loci, H. pylori genotype, and socio-economic factors on predicting H. pylori-associated distal gastric cancer in a southern European population.

MATERIAL AND METHODS

In a prospective case-control (1 : 2) study, 42 patients with H. pylori-associated distal gastric cancer were matched by age (+/-5 years) and gender to 84 patients with H. pylori-associated benign gastroduodenal disease (controls). The level of education received, smoking status, alcohol consumption, origin and familial history of gastric cancer were registered at inclusion. HLA DQA1 and DQB1 typing and H. pylori genotyping were determined from endoscopic gastric mucosal biopsies.

RESULTS

Compared with control patients, a positive association with cagA(+) strains (p < .002) and a negative association with vacA-s2 strains (p < .02) was found in patients with distal gastric cancer. At the DQB1 locus, the (*)0602 allele was more frequent in distal gastric cancer than in controls (26.2% vs. 4.8%; p < .005). After correction for multiple comparisons (exact multiple regression analysis) the cagA(+) status and the DQB1(*)0602 allele were associated with an increased distal gastric cancer risk (OR 3.7; 95% CI = 1.33-12.26 and OR 4.82; 95% CI = 1.24-19.83, respectively) whereas the vacA-s2 status was associated with a decreased risk (OR 0.33; 95% CI = 0.10-0.94).

CONCLUSION

Our findings suggest that in the H. pylori-infected southern European population, the cagA genotype and the HLA-DQB1(*)0602 gene confer an increased risk for distal gastric cancer.

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TNF and LTA gene polymorphisms reveal different risk in gastric and duodenal ulcer patients

A small proportion of patients infected with Helicobacter pylori or using non-steroidal anti-inflammatory drugs (NSAIDs) develops peptic ulcer disease. Since family studies have shown the importance of the genetic background of the host in the development of gastric and duodenal ulcers, immunogenetic factors involved in the regulation of inflammation deserve further study. Polymorphisms in the genes encoding tumour necrosis factor (TNF) and lymphotoxin-alpha (LTA) have been shown to contribute to the severity of infectious disease. Our aim was to study four bi-allelic polymorphisms in the TNF and LTA genes, which occur as five haplotypes, in patients with peptic ulcer disease. A total of 130 patients with duodenal ulcer, 50 with gastric ulcer and 102 ethnically-matched Spanish Caucasian healthy controls were studied. H. pylori infection was determined by invasive and non-invasive tests. Odds ratios were obtained by logistic regression analysis. H. pylori was detected in 91.8% of peptic ulcer patients and in 73.3% of controls (P < 0.001). Patients with gastric ulcer had a lower frequency of the TNF-308 allele 2 and a higher frequency of the LTANcoI 2.2 genotype when compared with duodenal ulcer patients (P < 0.01 and P = 0.03, respectively). Carriers of haplotype TNF-I were more frequent in gastric ulcer patients (49%) than in controls (28%) (P < 0.05) and the haplotype TNF-E was significantly more frequent in duodenal ulcers than in gastric ulcers (27% vs 8.2%; P < 0.01). Logistic regression analysis identified haplotype TNF-I carrier status as an independent risk factor for peptic ulceration in H. pylori-infected patients (OR: 4.2; 95%CI: 1.7-10.2). These results suggest that TNF and LTA gene polymorphisms are related to the development of gastric and duodenal ulcer and may determine disease outcome in H. pylori infection.