Analysis of peripheral blood lymphocyte phenotypes and Th1/Th2 cytokines profile in the systemic immune responses of Helicobacter pylori infected individuals.

H. pylori elicits specific humoral and cellular immune responses in the mucosal immune system. However, the type and extent of T lymphocyte response in the systemic immune system is not clear for H. pylori positive patients. In this study, peripheral blood T lymphocyte phenotypes and serum Th1/Th2 based cytokines of 32 H. pylori positive patients were analyzed and compared to those of healthy controls. While alphabeta TCR(+) lymphocytes and their phenotype analysis were not significantly different to those of healthy controls, the percentage of pan gammadelta TCR(+) lymphocytes was up to 2.4 times greater in the H. pylori positive group then in healthy controls. Furthermore, significant increases in IL-10 concentrations in serum samples of H. pylori patients indicated that their immune systems had switched toward a Th2 type immune response. The correlation between phenotype and type of T cell response in the peripheral blood during H. pylori infection is discussed.