Discovery could save lives of nut allergy sufferers

CHILDREN whose lives are at risk because of nut allergies could be saved after a breakthrough by Scottish scientists.

Researchers at Glasgow University have discovered a way of "turning down" the strength of serious reactions – known as anaphylactic shock – which can affect allergy sufferers.

Foods including peanuts and fish, as well as wasp or bee stings can in some cases lead to anaphylactic shock – a severe allergic reaction which can result in death.

Research suggests the UK has the highest rate of allergies in Europe and the figure is rising. Around one in 70 children in the UK – or maybe even as high as one in 50 – are thought to have a peanut allergy.

But allergies – and the severe reactions that sometimes result – can affect people of all ages. Researchers Dr Alirio Melendez and Professor Eddy Liew, from Glasgow University's Biomedical Research Centre, looked at patients who suffer anaphylaxis during surgery.

This can be caused by a reaction to the anaesthetic or other drugs which have been given. A large hospital can expect to see a case like this at least once a month.

The researchers found that patients who had anaphylaxis during surgery had higher levels of an immune hormone called IL-33 in their body.

The team are the first in the world to pinpoint a molecule that amplifies the allergic reaction. They have also developed a treatment to block it and reduce the symptoms.

Dr Melendez said: "Our study showed that IL-33 plays a pivotal role in hugely increasing the inflammation experienced during a period of anaphylactic shock and led us to understand how to intervene to reduce its impact. An anaphylactic shock prompts a massive inflammatory reaction which often is so severe that it constricts breathing.

"In our study we found that the severity of the shock is linked to the IL-33 molecule which acts as an amplifier to the inflammatory reaction.

"This can lead to a fatal constriction of the airway and, ultimately, death."

The researchers concluded that without high levels of the molecule, the allergic reaction would be far less severe and greatly reduce the risk of death.

They then went on to develop a treatment to block the IL-33 molecule in mice with reactions similar to those seen in patients during surgery.

The treatment – known as ST2 – successfully reduced the severity of the allergic reaction.

"This approach does not stop the allergic reaction altogether," Dr Melendez said.

"It blocks the amplification of the reaction triggered by IL-33, not the allergic response itself."

At the moment, people at risk of anaphylactic shock carry adrenaline injection kits in case they have an attack.

Dr Melendez said it was likely the new treatment could be used alongside adrenaline to reduce the risk of further attacks.

He said: "Some people have been injected and they get clear of this immediate response but then they get a secondary one which could even be the next day. That is what we could start preventing as well.

"Currently when a patient develops anaphylactic shock in the operating theatre it's roughly 50-50 if they survive or die.

Potentially with this type of therapy we can make them all survive."

The researchers, whose work is published in the journal Proceedings of the National Association of Sciences (PNAS), will extend their research to cover more allergies.

A major problem with food allergies is that products may not always make clear on their labels what they contain.

This could mean someone with a peanut allergy eating something by mistake which contains traces of nuts.

Food allergies make it difficult for people with the problem to eat out in restaurants or outside the home.

"What we studied was particularly the type of anaphylaxis you see in the operating theatre," Dr Melendez said.

"But potentially we want to make the correlation with patients who come with the shock due to peanut allergy or being stung by bees and so on."

The researchers hope to start clinical trials of their treatment within one to two years.

Lynne Regent, chief executive of The Anaphylaxis Campaign, said: "The results of the studyat The University of Glasgow, are encouraging.

"We would hope to see this work developed further to a point where it could be of real benefit to people living with anaphylaxis or at risk of severe allergic reaction.

"The Anaphylaxis Campaign is fully supportive of this type of reputable research and it will be particularly interesting to see how the findings can be delivered to the allergic population through the provision of adequate allergy services."