Assessment of immunological parameters in induced sputum in children with severe bronchial asthma

Severe bronchial asthma in children is an actual current problem, due to high risk of severe and/ or frequent exacerbations, decreased quality of life in patients and their families, as well as significant costs of socio-economic and medical resources. Personalized medicine suggests the need to search for specific objective indexes of the bronchial asthma severity in children. Biomarkers characterizing the inflammatory process may serve as indexes of the bronchial asthma severity. Aim of the study was to examine the amounts of surfactant protein A (SpA), Clara cell protein (CCP), interleukin-4 (IL-4), interleukin-6 (IL-6) and transforming growth factor β1 (TGF-β1) in induced sputum in children with severe bronchial asthma. 70 children took part in the study. The patients were grouped as follows: group 1, severe bronchial asthma (n = 24); comparison group 2 with mild bronchial asthma (n = 26). The control group 3 consisted of 20 healthy children. IS collection was performed according to standard methods. The concentrations of pneumoproteins and cytokines were determined in the induced sputum using ELISA techniques. In the group of patients with severe bronchial asthma, a statistically significant increase of SpA, CCP, IL-6 and TGF-β1 concentrations in induced sputum and a significant decrease of IL-4 levels was detected, when compared with mild asthma group and healthy persons (Kruskal-Wallis test, p < 0.05). Strongly positive correlations have been found between bronchial asthma severity and sputum proteins: for SpA (Spearman quotient r = 0.893814, p < 0.05); IL-6 (r = 0.827230, p < 0.05), and TGF-β1 (r = 0.886062, p < 0.05). The contents of studied pneumoproteins and cytokines reflect the severity of respiratory inflammatory process in children with bronchial asthma. The data on the IL-4 and IL-6 cytokine production in the group with severe bronchial asthma demonstrate involvement of other immune response types into allergic inflammation. The studied immunological parameters can serve as biomarkers of the asthma severity in children.