title: Cytotoxin-associated gene-A-seropositive virulent strains of Helicobacter pylori and atherosclerotic diseases: a systematic review.
abstract: OBJECTIVE
  A systematic meta-analysis was performed to explore the role of cytotoxin-associated gene-A (CagA) seropositive strains of Helicobacter pylori (H. pylori) in the pathogenesis of atherosclerotic diseases. Data sources Data from Medline, EMBASE, CBMdisc, CNKI and the Cochrane Collaboration database were searched. Similar search strategies were applied to each of these databases. Study selection The review was restricted to the case-control studies on infective, chronic virulent CagA strains of H. pylori, involving the risk of ischemic stroke and coronary heart disease, ineligible studies were excluded. Two reviewers independently extracted the data and assessed study quality.
  
  
  RESULTS
  Totally 26 case-control studies (11 studies on ischemic stroke and 15 studies on coronary heart disease) were retrieved and considered. The combined data revealed that the chronic seropositive virulent strains of H. pylori infection had a trend of increasing the risk of ischemic strokes and coronary heart diseases, yielding pooled ORs of 2.68 (95% CI: 2.20, 3.27) and 2.11 (95% CI: 1.70, 2.62), respectively. We also performed subgroup analyses, dividing the total population into Caucasian and Chinese subgroups. Through the subgroup analysis, no significant difference was found between the subgroups.
  
  
  CONCLUSIONS
  Our results support the hypothesis that CagA-seropositive strains infection is significantly associated with susceptibility to ischemic strokes and coronary heart diseases. The magnitude of the association with atherosclerotic diseases needs to be confirmed by prospective studies and the studies on CagA-seropositive strains eradication are more important.
authors.affiliation: Department of Neurology, Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.forename: Yue
authors.initials: Y
authors.lastname: Teng
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D050197:Atherosclerosis / Q000209:etiology* / Q000473:pathology; D001426:Bacterial Proteins / Q000276:immunology*; D016481:Helicobacter Infections / Q000097:blood / Q000150:complications* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori