Significance of TC9 and TH9 in Helicobacter pylori‐induced gastritis

Abstract Background H pylori plays a critical role in the development of stomach cancer, especially in people affected by the bacteria at an early stage of life. Th9 cells and IL‐9 play major roles in immune responses against various infections. IL‐9 is influential in chronic or acute inflammation of the mucosa. Aim This study seeks to investigate the possible functions of Tc9, Th9 cells, and IL‐9 level in patients with inflammation due to H pylori infection. Methods Eighty‐three patients with dyspepsia symptoms and twenty normal subjects with no sign and symptoms of dyspepsia were recruited. Frequencies of T‐cell subsets were determined by flow cytometry. Levels of cytokines IL‐9 family in the sera and supernatants of antigen‐activated PBMCs patients were measured by ELISA and flow cytometry. Results The participants included 56 females and 47 males with a mean age of 39.2 ± 15.3 years. We assigned the infected group into peptic ulcer and gastritis (chronic active and chronic). Frequencies of Tc9, Th17, Tc17, Th17/9, and Tc17/9 increased significantly in the peptic ulcer, chronic active, and chronic gastritis, compared with the uninfected and healthy control groups. A significant increase was seen in IL‐9, IL‐4, and IL‐23 in the chronic active gastritis. Further observed was a significant increase in IL‐21 and a decrease in IL‐10 in the infected groups. Conclusion The results revealed that increased Tc9, Th17/9, and Tc17/9 cells appear to be influential in the progression and severity of H pylori infection. Also, increased IL‐9 and IL‐4 levels and Tc9, Tc17/9, and Th17/9 were seen in chronic active gastritis patients. These findings may provide useful information for a therapeutic targeting of chronic active H pylori infections.