Severe bronchial asthma of childhood: phenotype or phenotypes?
Authors:   Bukovinian State Medical University, Chernivtsi, Ukraine, Koloskova O.K. , Ivanova L.A. ,   Bukovinian State Medical University, Chernivtsi, Ukraine, Tarnavska S.I. ,   Bukovinian State Medical University, Chernivtsi, Ukraine, Marusyk U.I. ,   Bukovinian State Medical University, Chernivtsi, Ukraine, Shakhova O.O. ,   Bukovinian State Medical University, Chernivtsi, Ukraine
Published: December 2024

The study of the phenotypes of severe bronchial asthma in children is extremely relevant. The frequent deterioration of the quality of children’s life, increased dissatisfaction with therapy due to the increased risk of adverse effects, the occurrence of side effects of treatment and the development of life-threatening exacerbations of asthma are urgent problems of pediatric allergology.
Aim - to study the diagnostic value of some clinical and spirographic indicators of severe bronchial asthma in order to optimize the verification of the variant of the disease in school-aged children.
Materials and methods. Сlinical and paraclinical examination was carried out of 359 children with bronchial asthma. 2 clinical groups were formed: the first (I) group was formed by 138 school-aged children with severe persistent bronchial asthma (average age - 11.7±0.3 years, the share of boys - 69.3%), and the second (II) group included 221 patients for moderately severe asthma (average age - 11.6±0.2 years; the share of boys - 72.9%). According to the main clinical characteristics, the groups were comparable.
Results. We found that the risk factors for severe asthma persistence associated with low birth weight (odds ratio - 2.2, relative risk - 1.4), early onset of the disease (odds ratio - 1.7, relative risk - 1.3), the triggering effect of acute respiratory infections on asthma exacerbations (odds ratio - 2.4, relative risk - 1.5). It has been established that patients with severe bronchial asthma have a higher non-specific hypersensitivity of the bronchi to direct and indirect broncho-provocative stimuli: indicators of a provocative concentration of histamine <1.0 mg/ml in the PC20H sample increase the chances of severe persistence of the disease by 5.4 times. The study of the diagnostic value in the verification of the phenotype of severe asthma for the provocation concentration of histamine <1.0 mg/ml in the PC20H sample is characterized by a sensitivity of 79.6% and a specificity of 57.9%, and for bronchospasm index >16.0% in a sample with physical exertion - sensitivity 32.8% and specificity of 81.1%.
Conclusions. Phenotype of severe asthma are determined by a combination of clinical, anamnestic and paraclinical signs of the disease, accompanied by pronounced hypersensitivity of the bronchi to indirect and direct irritants. At the same time, the existence of a single phenotype of severe asthma remains a matter of debate, or it is still advisable to mention several phenotypes of severe disease.
The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies.
No conflict of interests was declared by the authors.