Destruction of the bronchial epithelium in patients with severe asthma according to different patterns of inflammation and cold airway hyperresponsiveness

The aim of the research was to study the state of the bronchial mucosa epi-thelium in relation to the severity of clinical manifestations in severe uncon-trolled asthma depending on the pattern of inflammation and the presence of cold airway hyperresponsiveness. Materials and methods. In 48 patients with severe uncontrolled asthma, there were assessed asthma symptoms, clinical signs of cold airway hyperre-sponsiveness, and lung function; the samples of slides were analyzed in the cytological examination of the sputum; the degree of damage to epithelial cells and granulocytes was estimated using the total cell destruction index (CDI). Results. According to the analysis of sputum cytograms, the patients were divided into two groups: group I (22 patients) included persons with eosin-ophilic inflammation pattern (31.0±3.1% of eosinophils and 22.0±2.2% of neutrophils), group II (26 patients) was with mixed inflammation pattern (7.2±1.4 and 71.8±4.2%, respectively). The patients of group II had lower disease control according to Asthma Control Test (ACT; 12.1±0.7 and 17.8±0.2 points, respectively; р<0.05), a greater frequency of exacerbations (4.1±0.3 and 3.2±0.2 per year, respectively; р<0.05), greater incidence of clinical signs of cold airway hyperresponsiveness (79 and 19%, respectively; χ2=14.18; р<0.001); lower lung function (midexpiratory flow rate MEF25-75 was 14.6±1.6 and 20.7±1.9%, respectively; р<0.05); they received a higher dose of the combined medications of inhaled glucocorticosteroid in controller anti-inflammatory therapy (salmeterol/fluticasone at a dose of 705.3±19.7 and 650.7±14.8 µg/day for fluticasone propionate; р<0.05) In patients of group II the correlations of epithelial CDI with neutrophil CDI (r=0.61; p<0.01) and eosinophil CDI (r=0.48; p<0.05), as well as correlation of ACT with neutrophil CDI (r=-0.71; p<0.01) and eosinophil CDI (r=-0.53; p<0.05) were found. Conclusion. The degree of destruction of the epithelium and granulocytes in the inflammatory patterns has diagnostic relevance for the assessment of the severity of the disease, clinical manifestations of the airway response to the cold trigger, and the inertia of achieving control in patients with severe un-controlled asthma.

severe uncontrolled asthma, cold airway hyperresponsiveness, patterns of bronchial inflammation, destruction of epithelium