New Treatments Ease Peanut Allergy

Peanut Allergy Vaccine in the Works:Charcoal May Reduce Reactions

From the WebMD Archives

July 10, 2003 -- A promising experimental peanut allergy vaccine may soon provide lasting protection against potentially life-threatening reactions.

Though that day may still be years away, new research also shows that a common household item might provide immediate help in warding off or even preventing some severe allergic reactions.

Those studies, along with several other reports detailing new advances in peanut allergy detection, treatment, and prevention, appear in this month's issue of the Journal of Allergy and Clinical Immunology (JACI).

Peanut allergy is one of the most common food allergies, and 1.5 million Americans have severe peanut allergies that can be triggered by eating even a trace amount of peanut. Researchers say about half of all deaths due to food allergies are caused by peanut allergy alone.

Despite the severity and prevalence of peanut allergy, researchers say more than 80% of people who die from food-related anaphylaxis or severe allergic reaction had not been properly instructed on how to avoid or manage accidental exposure to food allergens or triggers.

A Peanut Allergy Vaccine?

Researchers say the recent discovery of the specific proteins in peanuts that are responsible for triggering an allergic reaction has now paved the way for vaccine development.

A study published in JACI describes a new technique using E. coli bacteria to deliver a vaccine in the form of a suppository that provided effective protection against peanut allergy for up to three months in mice bred to have peanut allergy.

Since genetically altered E. coli bacteria produce the proteins involved in peanut allergy reaction, researchers used an inactivated form of the bacteria to deliver the vaccine, which contained three different genetically modified forms of allergy-causing peanut protein.

"This gave us quite surprising protection as well as longer lasting protection than we've seen by any other method," says researcher Hugh A. Sampson, MD, of Mount Sinai School of Medicine in New York, who discussed the results of the study in a teleconference today.

"This particular vaccine that could be adopted for human use provides some hope that within the next several years we may be able to treat patients with peanut anaphylaxis and actually turn off the reaction so we no longer see symptoms."

Researchers say they hope to begin human trials of the vaccine within the next year. The vaccine would most likely be given over a series of about three doses using a teaspoon-sized gel suppository and may require yearly booster doses for best protection.


Activated Charcoal May Block Reactions

Although the vaccine study may be the most exciting news, JACI Editor Donald Y.M. Yeung, MD, PhD, says another study about using activated charcoal to curb peanut allergy reactions may provide more practical information.

Researcher Peter Vadas, MD, of St. Michael's Hospital in Toronto, and colleagues found that drinking activated charcoal immediately after accidental exposure to peanuts can block further absorption of allergy-causing proteins in the body and reduce the severity of allergic reactions. Activated charcoal is available at many pharmacies.

"Many parents have [the charcoal solution] at home to prevent poisoning, and if a patient accidentally ingests peanuts, this may be another approach to preventing a late reaction by keeping peanut in the stomach so it doesn't get absorbed into the bloodstream," says Leung, who is head of pediatric allergy-immunology at National Jewish Medical and Research Center in Denver.

But experts say early use of activated charcoal is by no means a substitute for using standard treatment for anaphylaxis, such as epinephrine (adrenaline), antihistamines, and seeking emergency medical treatment.

New Advances in a Nutshell

Other findings published in the journal include:

  • Regular treatment with an antibody called TNX-901 every four weeks for 16 weeks made patients less sensitive to peanuts, with most patients able to eat almost nine peanuts. Since accidental peanut ingestions usually involve amounts of less than two peanuts, researchers say long-term IgE therapy be an effective way to manage food allergies.
  • Measurement of a particular protein in the blood called peanut peptide-specific IgE may identify those at risk for allergic reactions.
  • People with a history of peanut allergy and peanut peptide-specific IgE levels of 5 or less have at least a 50% chance of outgrowing their allergy.
  • Food allergies, including peanut allergies, may be a risk factor for life-threatening asthma, and undiagnosed food allergies may trigger dangerous asthma attacks in children.
  • Despite common fears, casual skin contact or inhalation of peanut butter fumes will not usually cause a severe allergic reaction.
  • Commercial dry roasting of peanuts actually enhances the allergy-causing potential of peanuts by inhibiting a natural allergy fighter and may help explain why peanuts are such potent allergens.

"Based on the findings, the future looks brighter for the millions of patients and their families who live each day in fear that one bite of the wrong food that contains peanuts might cause a deadly reaction," says Anne Munoz-Furlong, founder/CEO of the Food Allergy & Anaphylaxis Network.

WebMD Health News Reviewed by Brunilda Nazario, MD on July 10, 2003


SOURCES: Journal of Allergy and Clinical Immunology, July 2003. Donald Y.M. Leung, MD, PhD, National Jewish Medical Center, Denver; editor of the Journal of Allergy and Clinical Immunology. Hugh A. Sampson, MD, Mt. Sinai School of Medicine, New York. Anne Munoz-Furlong, founder/CEO of the Food Allergy & Anaphylaxis Network. WebMD Medical Reference: "Understanding Anaphylaxis -- the Basics."

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