'Late' asthma research unearths potential new treatment
20 August BBC
Scientists have stumbled on a potential new treatment for delayed
asthma attacks which can occur several hours after exposure to
allergens, a study shows.
A team from Imperial College London found that blocking sensory nerve
functions stopped a "late asthmatic response" in mice and rats.
Around half of people with asthma experience delayed symptoms.
The charity Asthma UK says the research could help the understanding
of asthma.
Writing in the journal Thorax, researchers say the late asthmatic
response happens because the allergen triggers sensory nerves in the
airways. These nerves then set off a chain reaction which causes the
release of neurotransmitter acetylcholine, which causes the airways to
narrow.
If these findings translate to humans, it will mean that drugs called
anticholinergics - which block acetylcholine - could be used to treat
asthma patients who suffer from delayed attacks.
These attacks can often happen at night, three to eight hours after
the sufferer comes into contact with grass pollen or house-dust mites,
for example.A typical early asthmatic response occurs within an hour of
exposure to allergens.
At present, steroids are the main treatments for asthma but they are
not effective for all patients.
Connections Professor Maria Belvisi, lead researcher from the
National Heart and Lung Institute at Imperial College London, said they
realised the importance of sensory nerves in triggering symptoms by
chance.
"We wanted to do the research on anaesthetised rats, but we couldn't
because the late response had been blocked by anaesthetising them. "We
stumbled upon it. Now we want to work out how allergens trigger these
nerves, because we don't know the exact connections."
The data produced by the study suggests that anti-cholinergic therapy
may be effective in patients that observe a late phase response to
allergen.
Separate recent clinical studies also showed that an anti-cholinergic
improved symptoms and lung function in asthma patients.
Charity Asthma UK says 5.4 million people in the UK have asthma and
it can affect people at any age.
|