Improved understanding of severe asthma in children

Published Online: April 9, 2015

A small proportion of children with asthma suffer from a severe, therapy-resistant form of the disease and clinical care of these children remains a challenge. A child is diagnosed with therapy-resistant asthma when the disease cannot be controlled even with high doses of medication and all confounding factors (e.g. the presence of multiple chronic diseases, improper following of medical treatments, or allergen exposure) have been excluded. There is a great need to understand the mechanisms behind this disease in order to improve diagnosis and treatment. In a study recently published in The Journal of Allergy and Clinical Immunology (JACI), H. Persson and colleagues compared children with controlled asthma to those with severe therapy-resistant asthma and discovered striking differences in the white blood cells from these children.

Using blood samples collected during a nationwide Swedish study on severe childhood asthma, the authors measured the activity of the full complement of genes in white blood cells, and identified the genes that are turned on or off in children with controlled or severe therapy-resistant asthma, as well as a group of healthy controls. They also identified the regulatory genes that control these differences.

Surprisingly, a set of 1300 genes could accurately classify the children to their respective diagnostic groups. The authors also discovered several completely new variants of previously known genes that showed marked differences between patient groups, suggesting new disease markers for diagnostic use. The results also indicated that the glucocorticoid receptor, a major drug target in the treatment of asthma, has lower activity in the white blood cells from children with therapy-resistant asthma.

The study by Persson et al. suggests that therapy-resistant asthma in children is a separate disease from other forms of asthma that respond to drugs currently in use. Early identification of these patients is important, and the authors hope that the genes they have identified will be used as biomarkers in the clinic. Their findings suggest that a relatively simple blood test might be developed to aid in more accurate diagnosis, prognosis and choice of therapy in asthma, helping to improve disease management and reduce healthcare costs.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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