Clinical Brief – August 18th
New evidence finds that kids with peanut allergies can remain tolerant to peanuts 4 years after their initial course of treatment with peanuts and a probiotic.
What are you talking about?
In a study published this week, 67% of kids who were treated with a regimen of gradually increasing doses of peanuts and a probiotic, Lactobacillus rhamnosus, remained tolerant to peanuts – 4 years after they completed their treatment. Compare this to 4% of kids who had a placebo.
In an even smaller subset of volunteers, 58% of kids who were treated with peanuts and the probiotic remained unresponsive to peanut challenges for 8 straight weeks; vs 7% for placebo.
Very encouraging results, but consider that there were only 48 kids studied split 50/50 between treatment and placebo. The volunteer subset had only 12 kids in the treatment arm vs 15 on placebo. A much larger study is needed to confirm these results.
Still, very impressive given that these kids already had peanut allergies.
Back it up.
This study was a follow-up of a trial that was first published in 2015. Back then, researchers recruited 62 kids aged 1-10 with peanut allergies. About 4 in 10 of these kids had anaphylactic reactions to peanuts before the trial.
The kids were randomized 50/50 to a treatment of peanuts and the probiotic, or placebo.
Of course, giving a spoonful of peanut butter to a kid with a known peanut allergy is dangerous and ethically questionable. So, the protocol called for a gradual increase, from 0.1 mg per day all the way up to 2,000 mg per day, over the course of 24 days. Then they went on to have 2,000 mg per day for at least 6 months. At the same time, they took a fixed dose of the probiotic every day.
Two to five weeks after the treatment was over, the kids were challenged for 2 weeks straight to see if they were responsive to peanut challenges.
It turned out that the treatment worked: 82% of kids treated with peanuts and the probiotic completed the peanut challenges without a response vs only 4% for placebo.
“Thus if 9 children were given [peanut/probiotic] therapy, 7 would achieve possible sustained unresponsiveness.”
– Tang MLK, et al.
The study published this week followed up on these kids to see if they were allergic to peanuts 4 years after the treatment’s over.
Using the allergen to counteract the allergy is an idea borne out of the hygiene hypothesis, which suggests that being too careful about infections can be linked to a greater risk of developing allergies.
So far, this has supported research that looked at giving peanuts to kids thought to be at risk of developing peanut allergies later in life as a way to prevent peanut allergies.
But this study and the original trial is the first time I’ve seen peanuts being used to reverse an existing peanut allergy. Very cool. Would I try this at home? Probably not now.