Blood plasma cathepsin S in severe bronchial asthma

The aim. To determine the level of cathepsin S and to identify its possible relationships with clinical, functional and laboratory indicators in patients with severe bronchial asthma.Methods. 114 patients with severe bronchial asthma were examined. 96 women (84.2%) and 18 (15.8%) men were divided into 2 groups: allergic and non-allergic severe bronchial asthma. The external respiration function was assessed with whole-body plethysmography (“Erich Jaeger”, Germany). The plasma concentration of cytokines IL-4, IL-5, IL-13, periostin, cathepsin S, TGF-β was estimated with ELISA (“eBioscience”, USA).Results. Fixed obstruction is reported in 48% and 50% of cases of allergic and non-allergic severe asthma, respectively. Peripheral blood eosinophilia occurs in 41.5% of cases with allergic and in 25% of cases with non-allergic asthma. IL-5, IL-13, and cathepsin S levels were increased in both groups. An increase in IL-4 and TGF-β levels was revealed in non-allergic asthma. Periostin levels were increased in patients with allergic asthma as compared with the control and the second group. Positive correlation between cathepsin S and concentration of IL-4, IL-5 was established in both groups. We identified weak positive correlation between cathepsin S levels and clinical symptoms of the disease, such as frequency of SABA use and asphyxiation attacks, only in the allergic asthma group. A positive correlation between cathepsin S and TGF-β was established in both groups.Conclusion. A positive correlation between serum cathepsin S and TGF-β was established in both allergic and non-allergic severe bronchial asthma. The found moderate relationship may indirectly indicate the involvement of cathepsin S in airway remodeling processes regardless of the disease type.