New Clues to How Colds Can Spur Asthma Attacks
Finding provides new target for drug development, experts say
WEDNESDAY, Oct. 1, 2014 (HealthDay News) -- Scientists have pinpointed a molecule that may trigger potentially life-threatening asthma attacks brought on by colds.
The researchers say this finding could offer a target for new drugs to be developed to treat these attacks.
Most asthma attacks (80 percent to 90 percent) are caused by viruses that infected the airways, according to the British researchers. Most of these are rhinoviruses, which are the main cause of the common cold.
The researchers found that a specific molecule called IL-25 may play a major role in asthma attacks caused by colds. The findings are published in the Oct. 1 issue of Science Translational Medicine.
"Our research has shown for the first time that the cells that line the airways of asthmatics are more prone to producing a small molecule called IL-25, which then appears to trigger a chain of events that causes attacks," study co-lead author Nathan Bartlett, of the National Heart and Lung Institute at Imperial College London, said in a college news release.
"By targeting this molecule at the top of the cascade, we could potentially discover a much-needed new treatment to control this potentially life-threatening reaction in asthma sufferers," he added.
Samantha Walker is director of research and policy at Asthma UK. She stated in the news release: "Excitingly, this research, although still at an early stage, could potentially lead to the development of new medicines to prevent life-threatening asthma attacks."
For the study, researchers compared lung cells from people with asthma and from those without asthma. When infected with a rhinovirus, the lung cells from people with asthma produced about 10 times more IL-25 than lung cells from people without asthma.
In another experiment, the researchers infected volunteers with a rhinovirus and found that IL-25 levels were higher in the airways of people with asthma than in those without asthma.
The study authors also found that an antibody could block IL-25 in mice. They said the next step in this preliminary research is to test blocking the molecule in humans.
"Asthma attacks are still a huge health care problem," according to the study's other lead author, Dr. Sebastian Johnston.
"Existing medication containing inhaled steroids are highly effective at controlling regular asthma symptoms, but during an attack the symptoms worsen and can lead to the patient going to hospital," Johnston, a professor from the National Heart and Lung Institute at Imperial College London, explained in the college news release.
"This new study provides exciting results about potential ways to address this big unmet medical need. The next steps are to test blocking IL-25 in humans, and to investigate other possible pathways that could be important in asthma attacks and pool this knowledge to develop effective treatments," Johnston added.
About 235 million people worldwide have asthma, according to the World Health Organization.
The U.S. National Heart, Lung, and Blood Institute has more about asthma.