Open Access Research article

Higher frequency of cagA EPIYA-C Phosphorylation Sites in H. pylori strains from first-degree relatives of gastric cancer patients

Dulciene MM Queiroz2, Cícero ISM Silva1, Maria HRB Goncalves1, Manuel B Braga-Neto1, Andréa BC Fialho1, André MN Fialho2, Gifone A Rocha2, Andreia MC Rocha2, Sérgio A Batista2, Richard L Guerrant3, Aldo AM Lima4 and Lucia LBC Braga1*

Author Affiliations

1 Clinical Research Unity – Department of Internal Medicine, University Hospital Walter Cantídio – Federal University of Ceará, P.O. Box: 60430270, Fortaleza, Ceará, Brazil

2 Laboratory of Research in Bacteriology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

3 Center for Global Health, University of Virginia, Charlottesville, VA, USA

4 Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Ceará, Brazil

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BMC Gastroenterology 2012, 12:107  doi:10.1186/1471-230X-12-107

Published: 14 August 2012

Abstract

Background

To evaluate the prevalence of more virulent H. pylori genotypes in relatives of gastric cancer patients and in patients without family histories of gastric cancer.

Methods

We evaluated prospectively the prevalence of the infection by more virulent H. pylori strains in 60 relatives of gastric cancer patients comparing the results with those obtained from 49 patients without family histories of gastric cancer. H. pylori status was determined by the urease test, histology and presence of H. pylori ureA. The cytotoxin associated gene (cagA), the cagA-EPIYA and vacuolating cytotoxin gene (vacA) were typed by PCR and the cagA EPIYA typing was confirmed by sequencing.

Results

The gastric cancer relatives were significant and independently more frequently colonized by H. pylori strains with higher numbers of CagA-EPIYA-C segments (OR = 4.23, 95%CI = 1.53–11.69) and with the most virulent s1m1 vacA genotype (OR = 2.80, 95%CI = 1.04–7.51). Higher numbers of EPIYA-C segments were associated with increased gastric corpus inflammation, foveolar hyperplasia and atrophy. Infection by s1m1 vacA genotype was associated with increased antral and corpus gastritis.

Conclusions

We demonstrated that relatives of gastric cancer patients are more frequently colonized by the most virulent H. pylori cagA and vacA genotypes, which may contribute to increase the risk of gastric cancer.

Keywords:
Helicobacter pylori; Gastric cancer; H. pylori CagA-EPIYA; H. pylori/vacA