Caracterización de fenotipos de asma en niños del trópico

Abstract

Introduction: Asthma is a heterogeneous disease characterized by chronic inflammation of the airways and alteration of the type 2 (T2) immune response. This is characterized by the elevation of biomarkers such as the fractional exhaled nitric oxide (FeNO), peripheral blood eosinophilia and the presence of specific IgE against allergens. The distribution of these biomarkers and the phenotypes in asthmatic children in our population is not known.

Objective: Determine the main asthma phenotypes in a population of asthmatic children in Cartagena, Colombia.

Methodology: 107 children (age 7-17 years) with a previous diagnosis of asthma were recruited. Biomarkers of T2 inflammation were evaluated by measuring FeNO, eosinophil count in peripheral blood by hemocytometry, and determination of specific IgE to mite allergens by ELISA. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405).

Results: The average age of patients was 10.9 years. 19.6% of the children did not show elevation of any of the T2 inflammation biomarkers evaluated (FeNO <20ppb, eos <300/ul, negative specific IgE) so they were considered patients with non-allergic asthma (non-T2). 71.9% of all patients were sensitized to at least one allergen, this phenotype was considered allergic asthma. 30.8% of the patients presented the three elevated biomarkers (FeNO>20ppb + eos >300/ul + positive specific IgE), this phenotype was classified as high T2 allergic asthma. A moderate correlation (Spearman rho=0.44, p<0.0001) was found between FeNO values and eosinophil counts.

Conclusion: In this study, the following phenotypes were found: allergic asthma, high T2 asthma, and non-allergic asthma. Most patients presented a type 2 inflammatory phenotype with allergic sensitization. In addition to the measurement of specific IgE, the use of FeNO and eosinophil count in peripheral blood help to accurately determine those patients with high T2 asthma phenotypes.

Keywords: allergic asthma, non-allergic asthma, FeNO, eosinophilia, specific IgE

Funding: This study was funded by the SGR, project BPIN2020000100405 and the University of Cartagena.

Declaration of conflict of interest: The authors declare that they have no conflicts of interest in relation to this work.