Prevalence of CagA, VacA antibodies in symptomatic and asymptomatic children with Helicobocter pylori infection

Background. Limited data are available on the prevalence of CagA and VacA Helicobacter pylori antibodies in children. The aim of this study was to investigate the antibody prevalence to the H. pylori virulence factors CagA and VacA in symptomatic and asymptomatic children with H. pylori infection and to correlate these antibodies with the severity of gastric inflammation or density of H. pylori organisms in the gastric mucosa. Materials and Methods. Twenty-three symptomatic children and 132 asymptomatic children with positive H. pylori serology participated in this study. Anti-H. pylori IgG antibody and CagA or VacA H. pylori antibodies were measured by enzyme immunoassay (HM-CAP; sensitivity and specificity >90%) and Western immunoblot (Helicoblot 2.0) methods, respectively. Gastric inflammation and H. pylori density were graded histologically using the revised Sydney criteria. Results. The prevalence of CagA and VacA antibodies were 69% and 35% in symptomatic children and 54% and 52% in asymptomatic children, respectively. Multiple regression analysis showed a correlation between CagA antibody and the severity of gastritis but no correlation with other histological features, including the number of neutrophils or lymphoid follicles. Neither antibody correlated with the degree of bacterial density in the gastric mucosa. Conclusion. CagA and VacA H. pylori antibodies are common in the pediatric population. The combined CagA/VacA antibodies correlated weakly with the degree of mucosal inflammation.