An inverse relation between CagA+ strains of Helicobacter pylori infection and risk of erosive GERD

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. pyloriinfection 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). Conclusion: The CagA positive strains might have a protective effect against reflux esophagitis.