Helicobacter pylori infection: association of virulence factors with antigens of the HLA-system class II(locus DQ A1) in children with duodenal ulcer

Abstract

Background. Numerous epidemiological studies have shown that Helicobacter pylori (HP) infection is one of the most common in the world. The virulence of HP depends on the bacterial genotype. The purpose: to establish the relationship between the presence of antibodies to the CagA and BabA2 antigens of Helicobacter pylori and class II antigens of the HLA-system (locus DQ A1) in children with duodenal ulcer. Materials and methods. A comprehensive clinical and instrumental-laboratory examination was conducted in 140 children with duodenal ulcer aged 7 to 18 years (average age 12.3 ± 2.6) living in Chernivtsi and Chernivtsi region. Verification of HP was performed in biopsies from the body, antrum and duodenal bulb by the method of enzyme-linked immunosorbent assay (total antibodies to the CagA and BabA2 antigens of HP were detected). The genomic structure of HP was investigated by polymerase chain reaction. Results. Of the 140 HP(+) patients, the presence of HP was confirmed by polymerase chain reaction in 85.7 % of cases. Specific gravity of all strains with the presence of toxic genes is 71.7 % of all HP strains. The HLA DQ A1 antigen (χ2 = 4.29, P = 0.03), and the HLA-DQ A1 0103 0103 phenotypes (χ2 = 4.09, P = 0.04) were more likely to be detected in the examined group of patients with highly positive enzyme-linked immunosorbent assay results (antibody titer to CagA antigens of HP is 1 : 80). Conclusions. The high level of antibodies to the CagA antigen of Helicobacter pylori is associated with the antigen of the HLA-system class II DQ A1 0103, 0201.

Keywords

• duodenal ulcer
• helicobacter pylori
• hla-system