A drug used to treat multiple sclerosis could help reduce asthma attacks caused by the common cold virus.
Viral infections make asthma worse
A team from the University of Southampton found the cold virus was able to replicate at much higher levels in the lung cells of asthma patients.
But this replication was largely blocked in the laboratory when the cells were exposed to a form of the anti-MS drug interferon-B.
Details are published in the Journal of Experimental Medicine.
The common cold virus, or rhinovirus, is a major trigger for the worsening of asthma symptoms, frequently leading to the hospitalisation of sufferers.
Eight out of 10 asthma attacks in children and four out of 10 in adults are triggered by viral infections, such as colds or flu.
The cost to the NHS of hospitalisation for asthma sufferers in general is over £850m per year.
The Southampton team focused on epithelial cells taken from the surface of the lung which become infected by the cold virus.
They found the virus was able to reproduce itself at up to 50 times the normal rate in lung cells taken from asthma patients.
Analysis showed that the asthma patient cells contained low levels of a key chemical messenger called interferon-B.
Under normal circumstances, this chemical triggers infected cells to commit suicide, reducing the ability of the virus to spread through the lung tissue.
But the research suggests that in asthma patients, infected cells fail to sacrifice themselves, providing the cold virus with the ideal opportunity to thrive.
The Southampton team found that treating the cells with an interferon-B drug restored the normal balance, and helped to block the march of the virus.
Researcher Professor Donna Davies said: "The results suggest that inhaled interferon-B could be used in the treatment or prevention of rhinovirus-induced asthma attacks, thereby cutting the number of hospitalisations of asthma-sufferers during the cold season."
Dr Richard Russell, a chest specialist at Wexham Park Hospital, Slough, and a spokesman for the British Lung Foundation, told the BBC News website more research was required as the current study had been carried out in the lab, and not in patients.
But he said: "This research is potentially very important.
"We know that viruses are the main cause of exacerbated asthma symptoms in this country, and anything which could prevent the damage that people suffer as a result of viral infections would be very helpful."
Professor Martyn Partridge, of the charity Asthma UK, said: "All of the evidence does indeed suggest that many attacks of asthma are precipitated by viral infections.
"The current approach is therefore to teach those with asthma how to increase their asthma therapy to regain control of their condition.
"This latest work suggests that an approach directly on the virus may be feasible in the future but many detailed clinical studies will be needed first to confirm that this alternate strategy is effective."