A patch that contains a protein produced by house dust mites could revolutionise the treatment of asthma.
The patch, which is worn on the arm or stomach, gradually releases tiny amounts of the protein into the skin.
It is designed to “re-tune” the immune system so that it does not over-react when it comes into contact with mite droppings, which are a leading trigger for asthma attacks.
Once the body’s defences have learnt not to over-react — a process that can take several months — the patient can stop wearing the patch.
As well as treating existing asthma sufferers, it is hoped the new patch could also be used to prevent the disease developing in the first place in children.
House dust mites, which are related to the spider family, are usually less than half a millimetre long and whitish in colour. They thrive in dark and humid places at temperatures of around 25 degrees centigrade. As they feed on dead human skin cells, they gather in pillows, mattresses, clothing, carpets, upholstered seats and even soft toys.
The precise connection between asthma and dust mite allergy is unclear. However, it is thought to be linked to the proteins in their droppings.
When these are inhaled or touched by someone who is allergic to them, the proteins prompt the immune system to produce antibodies that cause the large-scale release of the chemical histamine.
It is this rush of histamine that leads to swelling and irritation of the airways, leading to breathing difficulties and asthma attacks.
Asthma sufferers who are sensitive to dust mite droppings are advised to take preventive measures.
These include wiping walls and floors with wet cloths, using plastic curtains and freezing cuddly toys once a month to kill off any mites they might harbour.
The skin patch — called ViaSkin — could be a more practical solution. A tiny capsule in the asthma patch contains manufactured versions of the harmful proteins found in dust mite droppings.
This form of treatment is known as immunotherapy and works by regularly exposing the immune system to tiny amounts of the offending protein. This daily exposure re-tunes the immune system so that it no longer interprets the proteins as a threat.
Older immunotherapy treatments involved injecting harmful proteins into the body to re-educate the immune system.
This involves frequent trips to hospital for jabs. And injecting a whole dose all at once carries the risk of triggering an extreme reaction.
The patch, which has so far been tested on mice, works differently — feeding a constant supply of tiny amounts through the skin, reducing the chances of an over-reaction by immune system cells.
The first human trials are planned for early next year. The same company is also using the technology to develop patches for peanut and milk allergies.
The US Food And Drug Administration has fast-tracked testing of the peanut patch in a bid to get it on the market as soon as possible.
Dr Samantha Walker, executive director of research and policy at Asthma UK, welcomed the breakthrough.
“Around 90 per cent of patients tell us house dust mites trigger their symptoms,” she says.
“This treatment could potentially improve the lives of many, as long as it turns out to be safe and does not cause severe allergic reactions, which other forms of allergen-specific treatments have been known to do.”
Meanwhile, a study has found that the removal of tonsils and adenoids reduces wheezing and breathlessness in children with a severe form of asthma.
The tonsils and adenoids (found at the back of the nose) are glands that help protect the throat from infections by trapping bacteria. They also contain immune cells.
Yet despite these apparent benefits, for asthma sufferers the glands may prove problematic.
In a study of 24 children and young adults (aged seven to 21) with asthma, carried out at the Children's Hospital and Research Centre in Oakland California, the removal of the glands produced an improvement in asthma symptoms.
The children, who were all asthmatics, had undergone surgery to treat sleep apnoea (a condition that causes the patient to stop breathing briefly at night, characterised by snoring), but the researchers also observed their asthma symptoms improved.
It is thought these glands can swell in an asthma attack, restricting air flow.
— Daily Mail
