Destructive-cytolytic and peroxidase activity of bronchial granulocytes in asthma patients with different levels of disease control

<b>Background:</b> An increase in the destructive-cytolytic and peroxidase activity of bronchial granulocytes is one of the factors of airway inflammation in asthma. We aimed to evaluate the activity of eosinophils and neutrophils in different levels of asthma control. <b>Methods:</b> In 38 patients with persistent asthma, the level of asthma control (ACT, points), lung function, airway response (ΔFEV1, %) to 3-min. isocapnic hyperventilation with cold air (IHCA), ultrasonic inhalation of distilled water (IDW) were assessed. In the induced sputum, the percentage of cells was calculated, and the activity of peroxidases (in pixels) was measured. The degree of cell damage was calculated using the cell damage index (CDI). The cytolysis index (IC) was calculated as the ratio of the most destroyed cells to the concentration of the rest of the damaged cells. <b>Results:</b> The patients were divided into group 1 with ACT&lt;20 points (n=19) and group 2 with ACT≥20 points (n=19). In group 1, CDI for eosinophils and neutrophils was 0.43±0.03 and 0.53±0.03, CI – 0.25±0,03 and 0.44±0.03, respectively. In group 2, CDI for eosinophils and neutrophils was 0.33±0.02 and 0.43±0.03, IC – 0.23±0.03 and 0.42±0.03, respectively. The level of peroxidase was 180 (75; 180) vs. 120 (60; 120) pixels (p=0.052). In group 1, a correlation was found between the peroxidase concentration in sputum and ΔFEV1 in response to IHCA (r=-0.55; p=0.022); between CDI of neutrophils and ∆MEF25-75 in response to IDW (r=-0.50; p=0.048). <b>Conclusion:</b> In patients with low asthma control, activation of destruction, cytolysis and peroxidase function of bronchial granulocytes related to airway responsiveness is observed.