title: An inverse relation between CagA+ strains of Helicobacter pylori infection and risk of erosive GERD.
abstract: OBJECTIVE
  The aim of this study is investigating the association of Helicobacter pylori (H. pylori) infection and its cytotoxic-associated gene A (cagA) strain with reflux esophagitis.
  
  
  METHODS
  In a case-control setting (May 2005-2006), patients with reflux esophagitis (case group) were compared with age and gender matched people suffering from symptoms of gastroesophageal reflux disease with normal upper gastrointestinal endoscopic findings (control group) in Imam Khomeini Hospital, Tabriz, Iran. The rates of H. pylori and its cagA positive infections were separately compared between the 2 groups and the subgroups with different severity of reflux esophagitis.
  
  
  RESULTS
  Ninety-two and 93 patients were enrolled in the case and the control groups. The rate of H. pylori infection was insignificantly lower in the case group (81.5% versus 87.10%, p=0.29, odd ratio 0.654, 95% Confidence interval [CI] 0.293 to 1.495). The CagA positive infections were found significantly more frequent in the control group (59.1% versus 40.2%, p=0.01, odd ratio 0.465, 95% CI 0.258 to 0.836). There was no significant difference between the severity subgroups of the disease for H. pylori (p=0.30) or cagA positive infection rates (p=0.40).
  
  
  CONCLUSIONS
  The CagA positive strains might have a protective effect against reflux esophagitis.
authors.affiliation: Liver & Gastroenterology Diseases Research Center, Tabriz Medical Sciences University, Tabriz, Iran. mhosseinsina@yahoo.com
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Somi
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Fattahi
authors.forename: Rohollah F
authors.initials: RF
authors.lastname: Fouladi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Karimi
authors.forename: Reza
authors.initials: R
authors.lastname: Bonyadi
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Baballou
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D016022:Case-Control Studies; D005260:Female; D005764:Gastroesophageal Reflux / Q000382:microbiology*; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori