Objective: The study aims to investigate the changes of interleukin (IL)-17 in induced sputum, and to observe the correlation between concentrations of IL-17 and the number of inflammatory cells in induced sputum in chronic obstructive pulmonary disease (COPD) and in asthma.
Methods: Induced sputum was obtained in patients with COPD both during acute exacerbation and stable stage and in asthma during acute attack. Healthy nonsmoking volunteers were included as controls. The concentrations of IL-17 in induced sputum were measured by enzyme-linked immunosorbent assay.
Results: The concentrations of IL-17 both in patients with COPD during acute exacerbation and with asthma were significantly higher than that in the control subjects (P < 0.001). The levels of IL-17 in patients with COPD during acute exacerbation positively correlated with that of IL-8 (r = 0.381, P = 0.038) and with the percentage of neutrophils (r = 0.446, P = 0.010) respectively. There was also a positive correlation between the concentrations of IL-17 and the numbers of eosinophils in patients with asthma.
Conclusion: The concentrations of IL-17 in patients with acute exacerbation of COPD and in patients with asthma were significantly increased. IL-17 may play a role in the airway inflammation in both COPD and asthma.