Seroprevalence of anti-Helicobacter pylori and anti-CagA IgG antibodies in dyspeptic patients of Kerman, Iran

Introduction and Objectives: Helicobacter pylori (H. pylori) infection is common worldwide and is the main pathogenic factor in the development of peptic ulcer disease. It has also been associated in the development of gastric cancers resulting from the cytotoxin-associated gene A (CagA). CagA-positive H. pylori strains has been more closely associated with gastric disease than CagA-negative isolates. The aim of this study was to evaluate the seroprevalence of anti-H. pylori and anti-CagA IgG antibodies in in a population of dyspeptic patients from Kerman, Iran. Materials and Methods: In this prospective epidemiological survey, a total of 659 people, ages 17 to 72 years, were evaluated for the presence of general anti-H. pylori IgG, and then 91 serum samples (70 seropositive for H. pylori IgG and 21 seronegative for H. pylori IgG, as control) for anti-CagA IgG by two commercial ELISA kits, according to manufacturer’s instruction. Results: The prevalence of general anti-H. pylori IgG was 58.1% (383 of 659 patients) that increased progressively with age (p<0.05) and was not appreciably influenced by the sex (p=0.08). Older patients showed a higher seroprevalence of H. pylori infection, in the age range from 51 to 72 years. 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. Conclusions: The findings suggest a relative high prevalence of H. pylori infection in dyspeptic patients of Kerman that was related to several risk factors as socioeconomic status and traditional living conditions. This is the first report of 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.