Bronchial inflammatory profile in interferon-gamma-mediated immune response in asthma patients during airway response to cold stimulus

Abstract Objective To evaluate the inflammatory pattern and the interferon (IFN)-γ in the bronchial secretion of asthma patients in response to acute cold bronchoprovocation. Material and methods We enrolled 42 patients with asthma. We assessed asthma by Asthma Control Test, the lung function by spirometry before and after the bronchodilator test, followed by collecting induced sputum. The next day, we collected exhaled breath condensate (EBC) and conducted a 3-minute isocapnic hyperventilation with cold air (IHCA), followed by collecting spontaneously produced sputum. Results Group 1 included 20 patients with cold airway hyperresponsiveness (CAHR), and group 2 included 22 patients without CAHR. In both groups, a high level of neutrophils in bronchial secretion was observed before and after IHCA. In response to IHCA, the number of epitheliocytes in the sputum decreased to a greater extent in patients of group 1. The baseline epitheliocytes and the concentration of IFN-γ after IHCA had an inverse relationship (r = −0.60; P = 0.017). The baseline IFN-γ in EBC before and after IHCA was lower in group 1. Airway response to cold exposure directly correlated with IFN-γ levels after IHCA (Rs = 0.42; P = 0.014). Conclusion In asthma patients with CAHR, there is a relationship between the persistence of mixed inflammation and the level of IFN-γ in the bronchi. IFN-γ in response to IHCA is decreased with increased cytokine utilization during cold bronchospasm, which is accompanied by the mobilization of neutrophils and the shift in the cytokine spectrum of the respiratory tract towards the T helper cells (Th) 1 immune response.