New Therapy May Knock Out Peanut Allergy
Experimental Treatment Gives Patients Tiny Amounts of Peanut Protein
March 16, 2009 (Washington, D.C.) -- Some kids with peanut allergies are now
packing peanut butter and jelly sandwiches for lunch, thanks to an experimental
treatment in which people with food allergies are fed miniscule amounts of the
very food to which they're allergic.
Five of nine children with peanut allergies who swallowed small doses of
peanut protein under a doctor's supervision daily for over two and one-half
years can now eat unlimited amounts of peanuts without any signs of allergic
Not only do they not develop hives, wheeze, or exhibit other symptoms, but
immune system changes suggest they've completely outgrown their allergies, says
Wesley Burks, MD, chief of the division of pediatric allergy and immunology at
Duke University Medical Center.
Burks presented the findings here at the annual meeting of the American
Academy of Asthma and Immunology.
About 12 million Americans have food allergies, and allergies to peanuts are
among the most dangerous. Life-threatening reactions can occur after simply
reusing a knife that wasn't properly scrubbed after being used to spread peanut
butter; nearly half of the 150 deaths attributed to food allergies each year
are caused by peanut allergies, Burks says.
Making matters worse, the number of people with peanut allergies doubled
over a recent five-year period, from four in 1,000 people in 1997 to eight in
1,000 in 2002, according to Robert Wood, MD, director of the division of
pediatric allergy and immunology at Johns Hopkins University School of Medicine
The bad news doesn't end there: Those ubiquitous allergy shots that are used
to combat allergies to insect stings and pollen are too risky for food
allergies. The only proven way to avoid allergic reactions is to avoid the
offending food, he tells WebMD.
Burks' team tried another tactic: oral immunotherapy. They gave 33 children
with known peanut allergy tiny but escalating doses of peanut protein in the
form of a powder sprinkled into applesauce or other food.
After eight to 10 months of the daily treatment, the children were
challenged with a doctor-supervised test in which they were given increasing
doses of peanut protein.
Most showed signs of desensitization, meaning that they could eat much
higher doses of the peanut protein before having an allergic reaction.
"At the start of the study, these participants couldn't tolerate
one-sixth of a peanut," Burks says. "Six months into it, they were
ingesting 13 to 15 peanuts before they had a reaction."
Their parents benefited, too. "Their anxiety levels about going out to
eat, even just sending their kids to school, really went down," he
Four youngsters couldn't tolerate the treatment and dropped out of the
Of the other 29, nine kids have now been in the study for more than two
and a half years. Five of the 29 have been able to stop treatment because
they can tolerate peanuts in their regular diet. The other four children remain
on daily maintenance treatment.
The researchers also looked at blood markers of immune system response,
including immunoglobulin E (IgE), a protein the body makes in response to
allergens. "It tells you the likelihood that you're allergic," Burks
says. IgE levels dropped in all the kids, but they went down faster in the
children who are now able to eat peanuts with impunity, he says.