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