Genetic biomarker opens doors to new therapies for hard-to-treat asthma
Asthma specialists may one day be able to use a biomarker to more easily identify and treat children whose asthma attacks do not respond well to commonly prescribed corticosteroids.
The discovery of the biomarker VNN-1, reported April 21, 2014, in The Journal of Allergy and Clinical Immunology, provides a genetic basis for understanding why some children with asthma respond effectively to medicines that control underlying inflammation – and why other children do not. It also holds out hope that difficult-to-treat patients can be identified quickly, and that researchers can find better therapies for asthma, which affects 7 million children in the U.S.
Gurjit Khurana Hershey, MD, PhD, director of Asthma Research, and her team collected and tested cells from the nasal passages of 57 children whose emergency room visits for acute asthma required hospitalization. From a list of 20,000 gene candidates, doctors singled out and tested one gene, vanin-1 or VNN1, as the primary target for their study.
According to Hershey, expression of the VNN-1 gene helps discriminate between good and poor responders to corticosteroids.
Lab tests showed that VNN-1 expression is required for inhaled corticosteroids to provide relief during an asthma attack. Children whose asthma did not respond well to corticosteroids exhibited a biochemical variation of VNN-1 that hindered its expression. Subsequent tests on laboratory mouse models of asthma suggested that targeting the VNN-1 pathway therapeutically might be valuable for improving outcomes for difficult-to-treat patients.
