Sprinkle of powder can ‘cure’ peanut allergy
APOWDER sprinkled on food every day may banish severe peanut allergies. The powder has tiny traces of the proteins in peanuts that can trigger potentially fatal reactions. By gradually increasing the amount of these proteins consumed over several months, doctors believe they can help patients’ immune systems become tolerant to them, eventually eradicating the risk of lifethreatening reactions.
A trial is under way in the U.S. and Europe to find out whether consuming the powder every day for 20 weeks will increase tolerance to the point where it is safe to eat small amounts of nuts.
This type of treatment is already used by a handful of specialist allergy clinics in the UK. But it usually involves patients ingesting tiny quantities of nuts themselves to gradually build up tolerance.
While this can be effective, it involves a lot of trial and error, as nuts’ protein content can vary greatly, making it hard to precisely monitor intake and increasing the risk of an abnormal reaction.
The scientists behind the powder say it can be made to contain precise doses of nut protein, from less than 0.5mg up to 300 mg. This gives doctors greater control over how much protein patients ingest.
Around one in 100 people in the UK has a peanut allergy. When their immune system comes into contact with any of the three types of peanut protein (Ara h1, Ara h2 and Ara h3), it mistakenly treats them as a threat, releasing chemicals to destroy what it perceives as a dangerous invader.
ONE of the main chemicals is immunoglobulin E, an antibody pumped out in large volumes to repel the suspected attack. This rush of chemicals triggers symptoms of an allergic reaction, often within seconds. These range from an itchy mouth to anaphylactic shock, where the airways narrow, blood pressure plummets and organs start to shut down.
Sufferers who have had severe reactions usually carry an EpiPen device to give themselves a shot of adrenaline if another reaction occurs. This opens up the airways and dilates blood vessels to force blood pressure back up.
The new medicine — codenamed AR101 — is a drug and not a food supplement. It comes in capsules containing predetermined doses of nut protein in powder form. Once the capsule is cracked open, the flavourless powder is sprinkled on foods in which it can be easily dispersed, such as mashed potato. In a 2016 U.S. trial, 40 patients with severe allergies were put on the daily powder for 12 weeks.
Once a fortnight, doctors gave them slightly more; they were told to stop at the first sign of symptoms, such as hives or tingling in the mouth. Once this resolved, the dose would be increased again.
The results, which are awaiting publication, but were released at a conference in 2016, showed some patients who previously suffered reactions when they ate the equivalent of less than one peanut could tolerate seven or eight nuts.
In the new trial, more than 500 patients will receive similar treatment, but over a 20week period, to see if longer treatment will lead to even greater tolerance.
The U.S. regulator, the Food and Drug Administration, recently granted the drug ‘Fast Track designation’ to speed its progression through the approval process. It could be available for UK patients within the next two years.
Anthony Frew, a professor of allergy and respiratory medicine at the Royal Sussex County Hospital in Brighton, said while the powder could benefit sufferers, the effects may be temporary — as with similar existing treatments.
He adds: ‘If you stop having the peanut protein daily, tolerance wears off, so you may have to keep consuming this powder for ever.’
MEANWHILE, researchers at Mount Sinai Hospital in New York have identified six genes that set off peanut allergies. They monitored 40 nut allergy patients’ immune reactions before, during and after consuming peanuts or a placebo, an oat powder.
They took blood samples to monitor the action of genes and different processes within cells.
The hope is that this will lead to ways to prevent and treat reactions, reported the journal Nature Communications.