Background and objective: Biphasic cellular immune reactions, which follow allergen inhalation, are a specific feature of inflammation in allergic asthma. The aim of this study was to determine the changes in the percentage of peripheral blood Th17 cells and neutrophil functions after Dermatophagoides pteronyssinus-induced early- and late-phase asthmatic response in patients with allergic asthma.
Material and methods: A total of 19 patients with allergic asthma were examined. Eleven patients developed an isolated early-phase asthmatic response (EAR), whereas 8 developed both early- and late-phase (dual) asthmatic responses (DAR) after the bronchial challenge with Dermatophagoides pteronyssinus. The control group included 15 healthy subjects. Peripheral blood collection was performed 24 hours before as well as 7 and 24 hours after the bronchial challenge. The percentage of Th17 cells, and chemotaxis and apoptosis of neutrophils were analyzed by flow cytometry. The serum IL-8 and IL-17 levels were determined by ELISA.
Results: After the bronchial challenge, the percentage of Th17 and IL-17 levels increased considerably 7 and 24 hours after the challenge in both groups of patients. Moreover, 24 hours after the challenge, the percentage of Th17 cells and IL-17 levels were significantly higher in the patients with the DAR than those with the EAR or healthy controls. Seven and 24 hours after the challenge, neutrophil chemotaxis was greater in the patients with the DAR as compared with those with the EAR and healthy controls as well. The apoptotic activity of neutrophils was lower 24 hours after the challenge in the patients with the DAR than those with the EAR.
Conclusions: Dermatophagoides pteronyssinus-induced early- and late-phase asthmatic response in patients with allergic asthma was found to be accompanied by an increased percentage of peripheral blood Th17 cells and elevated serum IL-17 levels as well as altered neutrophil functions.