Association of the CagA status of Helicobacter pylori and serum levels of interleukin (IL)‐17 and IL‐23 in duodenal ulcer patients

Abstract

It has been reported that the cytotoxin-associated gene A (cagA+) H. pylori strains induce severe gastric mucosal inflammation. The aim of this study was to investigate the association of the virulence factor CagA with IL-17 and IL-23 serum levels in duodenal ulcer (DU) patients and H. pylori-infected asymptomatic (AS) carriers. In total, 45 H. pylori-infected DU patients were enrolled to study: 23 tested positive for the anti-CagA antibody (anti-CagA+) and 22 tested negative for the anti-CagA antibody (anti-CagA-), 30 were AS carriers (15 were anti-CagA+ and 15 were anti-CagA-) and 15 were healthy uninfected participants (as a control group). The IL-17 and IL-23 serum levels of participants were measured by enzyme-linked immunosorbent assay method. The mean IL-17 levels in DU patients were significantly higher than those in AS and control groups (P < 0.001 and P < 0.0001 respectively). In the DU group, the mean IL-17 levels in participants testing positive for anti-CagA (10.84 +/- 5.79 pg/mL) were significantly higher than those observed in participants testing negative for anti-CagA (7.65 +/- 4.74 pg/mL; P < 0.05). The mean IL-23 levels in the DU and AS groups were significantly higher than in the control group (P < 0.02 and P < 0.03 respectively) but were not significantly different in participants testing positive and negative for anti-CagA. These results showed higher IL-17 and IL-23 serum levels in H. pylori-infected participants than in the control group. In the DU group the expression of IL-17 was influenced by the CagA factor.