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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.