Seroprevalence of Anti-Helicobacter pylori and Anti-CagA IgG Antibodies in Iranian Dyspeptic Patients

Background: Helicobacter pylori, a worldwide infection, is associated with several infectious diseases including gastric ulcer, peptic ulcer, and gastric cancer resulting from the cytotoxinassociated gene A (CagA). The purpose of this study was to evaluate the seroprevalence of anti-H. pylori and anti-CagA IgG antibodies in Iranian dyspeptic patients. Methods: In this prospective epidemiological survey, a total of 659 patients were evaluated for the presence of general anti-H. pylori IgG, and then for anti-CagA IgG by two commercial ELISA kits. Results: The prevalence of general anti-H. pylori IgG was 58.1% (383 of 659 patients) which increased progressively with age (P<0.05) and was not significantly influenced by the sex (P=0.08). The prevalence of anti-CagA IgG antibody in seropositive and seronegative patients for general H. pylori IgG was 52.9% (37 of 70) and 61.9% (13 of 21), respectively. Conclusion: This is the first report on the high prevalence of anti-CagA IgG in both seropositive and seronegative patients for general IgG, indicating the importance of this antibody in diagnosis of H. pylori positive patients after seroconversion of the general IgG.