The Changes in the Levels of IL-6, IL-17, and IL-21 in the Acute Stage of Childhood Asthma

Background: Asthma is the most common disease in children, and its pathogenesis is highly complicated. Methods: CD4(+) cells and CD4(+)IL-17(+) cells were analysed by flow cytometry, and the ratio of CD4(+) cells to the peripheral blood mononuclear cells (PBMCs) and CD4(+)IL-17(+) cells to PMBCs were calculated from the control group, acute group, and moderate group. The levels of protein expression of IL-6, IL-17, and IL-21 were detected by ELISA in the plasma and culture supernatants of PBMCs of the three groups. The correlations between IL-7 and IL-6, IL-7 and IL-21 were analysed in culture supernatants of PBMCs of the three groups. Results: The mean ratio of CD4(+)IL-17(+) cells/peripheral blood mononuclear cells (PBMCs) was 4.32% in the acute group, which was higher than in the control group and moderate group. The levels of IL-6 and IL-17 were elevated, and the levels of IL-21 were decreased in the acute group. The levels of IL-17 and IL-6 were positively correlated (r = 0.182, p = 0.03), and the levels of IL-17 and IL-21 were negatively correlated (r = -0.834, p = 0.02). Conclusions: The results suggest that the levels of IL-17 and IL-6 are related to the severity of asthma. Furthermore, IL-17 may play a role in the development of childhood asthma.