Significance of laboratory parameters of cellular compositionof peripheral blood for assessment of steroid resistance in patients with chronic obstructive pulmonary disease
Inhaled corticosteroids are often used for treatment of chronic obstructive pulmonary disease (COPD), but their effectiveness significantly varies in different patients. The aim of the study was to determine the significance of measurement of cellular composition of peripheral blood for assessment of effectiveness of response to glucocorticoid therapy in patients with COPD. The study included 45 patients with COPD, who underwent bronchoscopy and general blood analysis. Alveolar macrophages isolated from bronchoalveolar lavage fluid were cultured with lipopolysaccharide (LPS) and different concentrations of dexamethasone (0.01-1000 nM). In 24 hours, supernatants were removed and analyzed for the concentration of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and IL-8. IL-8 production was less sensitive to inhibition of corticosteroids than IL-6 and TNF-α synthesis. The ability of dexamethasone to reach 50% inhibition of interleukin-8 production by alveolar macrophages was used for division of all patients with COPD into steroid-sensitive and steroid-resistant ones. Absolute and relative neutrophil numbers, absolute number of platelets were higher; absolute and relative eosinophil numbers, relative lymphocyte number were lower in steroid-resistant patients with COPD, if compared with steroid-sensitive ones. These parameters are diagnostically significant for prediction of steroid resistance in patients with COPD. Their diagnostic accuracy varies between 66.7% and 80.0%. Complete blood count parameters can be used for assessment of glucocorticoid response before treatment of patients with COPD.