The paper presents data on the detection of an autoimmune process in the bronchopulmonary system in children with BA aged from 5 to 14 years in the period of exacerbation. The comparison group consisted of 25 healthy children aged from 7 to 14 years. It has been shown that lipopolysaccharide antigens from the interstitial connective tissue of bronchopulmonary structures obtained from accidentally killed children have a higher specificity than protein antigens and allow identifying morphological changes in the bronchopulmonary system, the severity of the course and monitoring the effectiveness of the therapy. Antigens obtained from the sectional material of the bronchopulmonary system of protein nature cannot be obtained industrially, since they are not standardized for protein, do not possess sterility, which greatly limits their use and reduces the diagnostic value. The multicomponent antigenic composition of protein homogenates obtained from the cell-tissue structures of the bronchopulmonary system does not clearly identify the nature of the morphological changes in bronchial asthma in children. Lipopolysaccharide antigens from bronchopulmonary structures do not contain protein in their composition; they can be obtained industrially under sterile conditions and stored in a lyophilized state for more than two years, which allows them to be widely used in immunodiagnostics of clinical forms and severity of asthma in children.