авг 21, 2017
Breakthrough Peanut Allergy Treatment Still Amazingly Effective After 4 Years
If you're one of those people who can't even be in the same room with a deadly food allergen such as a peanut, you probably think scientists are not moving fast enough in terms of finding a cure.
But now some amazing follow-up results of a clinical trial in kids with peanut allergies have demonstrated that it may actually be possible to achieve lasting peanut tolerance for people with this distressing condition.
"Studies have shown that quality of life for a child with peanut allergy is actually worse than for a child who has diabetes," says lead researcher Mimi Tang from Murdoch Childrens Research Institute in Australia, adding that it's almost impossible to manage the allergy by simply avoiding the offending legumes.
Researchers have already made progress in treating peanut allergies with oral immunotherapy - which basically means eating tiny amounts of the peanut allergen until the immune system is desensitised.
Unfortunately so far that approach has not produced long-lasting results, and the allergic response comes roaring back in most cases once the therapy is stopped.
To see if they could get a sustained effect from immunotherapy, the team came up with a fresh strategy, pairing the peanut allergen with a probiotic that can give the immune system an additional nudge in the right direction to stop treating peanuts as enemy.
The probiotic, Lactobacillus rhamnosus, is one of those 'friendly germs' you can find in yoghurt, although the researchers used a far more concentrated dose - you'd have to eat at least 20 one-kilogram tubs a day to get the same effect (please don't do this).
The initial results of the trial were published in 2015, showing that after a year, 82 percent of participants (23 of 28 kids) treated with the combined therapy could eat peanuts without consequences - a state the researchers call 'sustained unresponsiveness'.
In contrast, only one kid (out of 28) in the placebo group became desensitised to peanuts. Kids sometimes 'grow out' of allergies, so it's not entirely weird. (If you're wondering what a peanut paste placebo would look like, it was "maltodextrin, brown food colouring, and peanut essence".)
Now the follow-up data is in, with extremely encouraging results. The researchers didn't manage to follow up with all the participants, but four years after last receiving the treatment, 16 of 24 kids who received the combined probiotic therapy are still able to eat peanuts, even just occasionally.
That's pretty amazing.
"[In] no other study of oral immunotherapy have individuals been able to ingest the allergen with this infrequency and remain non-reactive," pediatric immunologist Matthew Greenhawt from the University of Colorado writes in an accompanying comment article about the study.
To further test their results, the team also asked participants if they'd do a double-blind, placebo-controlled food challenge test, which involves cutting out peanuts for eight weeks and the introducing them back.
"Eighty percent of children who achieved tolerance after the first trial were still eating peanuts four years later, and 70 percent of those actually passed this tolerance challenge," says Tang.
"So we were very excited by these findings, because to us it really shows that the probiotic-peanut combination can really change the immune response to peanuts."
Earlier this year the US National Institutes of Health (NIH) updated their guidelines on feeding peanuts to young children, changing the prevailing wisdom that kids should avoid peanuts early in life.
Instead, the advice now states that high-risk babies - those who already have egg allergy or severe eczema - should eat peanut-containing foods as early as four months of age.
"Preventing the development of peanut allergy will improve and save lives and lower healthcare costs," NIH representative Anthony Fauci said in January.
"We expect that widespread implementation of these guidelines by healthcare providers will prevent the development of peanut allergy in many susceptible children."
And now the results of this latest trial show that not only are we getting better at preventing peanut allergies, but we're also well underway to finally having a lasting treatment.
The results were published in The Lancet Child & Adolescent Health.