Interleukin 8 and bronchial phagocytes in patients with non-allergic asthma and diverse respiratory responses to cold stimulus

Introduction . The role of phagocytes, regulated by interleukin 8 (IL-8), in the formation of the bronchial response to environmental stimuli in patients with asthma is not well understood. Aim . To study the functional activity of IL-8 and the pool of phagocytic cells in the inflammatory pattern of the bronchi in patients with non-allergic asthma during inhalation exposure to cold air. Materials and methods . In 129 patients with mild to moderate asthma, the content of IL-8 and the cellular composition of sputum before and after the bronchoprovocation test with isocapnic hyperventilation with cold air (-20°C) (IHCA) were analyzed. Results . Based on the results of the IHCA by the assessment of changes in FEV1 (Δ,%), 54 patients (1st group) were verified with cold airway hyperresponsiveness (CAHR), the comparison group consisted of asthma patients (2nd group, n=75) who did not respond to the trigger (ΔFEV1 = -18.9±1.2 and -3.3±0.4%; p<0.0001, respectively). The content of neutrophils in sputum before provocation was 41.1±2.2% and 34.5±2.2% (p><0.05), macrophages – 36.2±2.7% and 43.1±2.5% (p> ˂ 0.0001, respectively). The content of neutrophils in sputum before provocation was 41.1±2.2% and 34.5±2.2% (p ˂ 0.05), macrophages – 36.2±2.7% and 43.1±2.5% (p>0.05), respectively. In response to the IHCA in the 1st group, the number of neutrophils increased to 48.2±2.0% (p ˂ 0.05), macrophages decreased to 28.7±2.1% (p ˂ 0.01), and the level of IL-8 increased from 12838±2328 to 17412±2980 pg/mL (p ˂ 0.05). In the 2nd group, the concentration of IL-8 before the IHCA was 14639±2691 pg/mL, after the test 10545±1746 pg/mL (p>0.05); the number of neutrophils after the test 40.0±2.3% (p>0.05); macrophages – 35.8±2.0% (p ˂ 0.01). Conclusion . In asthma patients with CAHR, the inflammatory pattern of the bronchi in response to the cold trigger shows enhanced IL-8 activity and more pronounced changes in the content of phagocytes, mobilized with the involvement of this cytokine.