Current knowledge of bronchial asthma with low T2-inflammation in school-aged children (review)

Bronchial asthma in children is a heterogeneous disease; therefore, determination of the disease endotype is important for personalized therapy, overcoming refractoriness to bronchial asthma treatment, and selecting a targeted biologic drug. The endotype of the disease, which is not associated with eosinophilia and, therefore, characterized by an insufficient response to inhaled corticosteroids, may begin at school age. The prevalence of low T2-inflammatory bronchial asthma in school-aged children is poorly understood, but the evidence presented in this article supports the presence of this endotype. This endotype of bronchial asthma in children is characterized by clinical and pathogenetic features, including low degree of allergic sensitization, reduced level of total IgE, limited number of positive allergy tests, decreased concentration of nitric oxide in exhaled air and eosinophil content in blood. The role of neutrophils in the development and prognosis of bronchial asthma in children is currently insufficiently studied and defined, nevertheless, it is known that the neutrophilic type of inflammation is associated with a more severe course of the disease and inadequate control. It is important to emphasize the need for further research into the endotypes of bronchial asthma in children with the identification of novel biomarkers and molecular mechanisms underlying asthma with low T2-inflammation. This may further enable the achievement of control of bronchial asthma with different inflammatory endotypes.