The prevalence of anti-CagA and anti-VacA antibodies in children with Helicobacter pylori infection

Abstract
Introduction: Helicobacter pylori (H. pylori) infection is acquired mainly in childhood. The type of clinical manifestation is associated not only with specific virulence factors of these organisms but also with host immunological response.
Aim: The aim of the study was to determine the frequency of IgG antibodies against H. pylori specific antigens CagA (120 kDa) and VacA (95 kDa) in children with different gastroduodenal diseases.
Material and methods: Serum samples taken from children (n = 200), aged 4-18 years, with chronic gastritis (n = 130), peptic and duodenal ulcer disease (n = 39), gastroduodenal reflux disease (GERD) (n = 19) and coeliac disease (n = 12), were examined. The presence of anti-H. pylori IgG antibodies was detected in patients’ sera by ELISA and Western blot.
Results: Among examined samples antibodies against H. pylori CagA were observed in 70% of cases. In children with chronic gastritis the percentage of antibodies against 120 kDa, 95 kDa H. pylori antigens was 61.54 and 37.69%, whereas in subjects with peptic and duodenal ulcers it was 92.31 and 82.05% respectively. In patients with coeliac disease the level of anti-CagA and anti-VacA antibodies was as high as 83.33 and 75%. The highest frequency of the presence of anti-H. pylori specific antibodies was observed in the youngest children (84%).
Conclusions: Specific antibodies against CagA and VacA are observed more frequently in children with peptic and duodenal ulcer than in patients with chronic gastritis. A high prevalence of the presence of antibodies against VacA and CagA in very small children could be associated with high rate of infection caused by CagA+, VacA+ H. pylori strains in Lower Silesia region.