Biomarkers of airway inflammation and asthma symptom control in children

INTRODUCTION Bronchial asthma (BA) is a heterogeneous pulmonary disease with various phenotypes based on detection of multiple biomarkers. However, most of the biomarkers are still experimental and present limitations for clinical practice. OBJECTIVE The purpose of this study was to investigate the relationship between the level of the available T2-inflammatory biomarkers in childhood with poor asthma control and features of asthma management. MATERIAL AND METHODS The study comprised 100 patients aged 5–17 years (median age 13 years) with an established bronchial asthma diagnosis. The level of asthma control of each patient was assessed by the Asthma Control Test (ACT and C-ACT) and the Composite Asthma Severity Index (CASI). T2-inflammatory biomarkers of the mucous membranes of the respiratory tract include total immunoglobulin E (IgE total) levels, peripheral blood eosinophil levels, fractional exhaled nitric oxide (FeNO) and a nasal smear eosinophil count. A measure of association was determined by standard statistical methods for data analysis. RESULTS Despite the prescribed basic therapy, the majority of children do not achieve adequate asthma symptom control. This research revealed that 43% of patients had at least one or more elevated markers of T2-inflammation. High levels of IgE total, increased levels of blood eosinophils (≥400 cells/µL), as well as high FeNO values (≥ 20 ppb) prevail in children with partially controlled and uncontrolled asthma. The most significant biomarker of poor asthma control in children is the total serum IgE concentration ≥ 100 IU/ml. In addition, a significant positive correlation was found between peripheral blood eosinophil levels and the ACT/C-ACT scores (r=0.287, p=0.0039). CONCLUSION Allergic asthma in children is typically associated with Th2-lymphocytes predominance and eosinophilic airway inflammation. T2-inflammatory biomarkers may be useful in assessing airway inflammation activity and asthma-control assessment in children. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The research was supported by a joint grant from the Ministry of Science and Technology of Israel (MOST, 3-16500) and the Russian Foundation for Basic Research (research project 19-515-06001). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The local ethics committee at the Academician E.A. Wagner Perm State Medical University of the Ministry of Health of Russia Approval Code: 5/20 Approval Date: 08.04.20 I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors