New research out of Australia holds great promise. A study team announced in December, 2010 that they had discovered fragments of peanut protein that may be the key component to a peanut vaccine that could be given by injection.

Allergic Living’s Lisa Ferlaino spoke with Dr. Robyn O’Hehir, the team’s leader and a professor of allergy and immunology at Monash University in Australia, about the discovery and what it means.

Why the focus on immunotherapy as a treatment for peanut allergy?

“Allergen immunotherapy is the only treatment that can actually change the natural course of allergic diseases. We know from the aero-allergens such as house dust mites and grass pollens, and even from bee and wasp venom, that allergy shots make a big difference in people’s lives. That’s what we’re striving for.

We also know that peanut allergy is becoming more common worldwide, and that people find traces of peanut in unexpected foods. That’s one of the reasons avoidance isn’t really sufficient.”

Peanuts have long been viewed as too risky for immunotherapy, too likely to provoke anaphylaxis. How do you address that?

“By studying the white blood cells of patients with peanut allergy, we’ve been able to narrow down the core epitopes – the critical fragments of peanut protein that drive the allergic response in people with peanut allergy – and we’ve identified ones that are too small to cause anaphylaxis. They won’t bind to IgE [allergy antibodies], but they’re big enough to kickstart the immune system to develop tolerance.”

Are these fragments parts of peanut’s infamous Ara h 1 and Ara h 2 proteins?

“Yes. We’ve identified the critical peptides [protein fragments] in Ara h 2, the major peanut allergen. That’s the one most associated with anaphylaxis. Ara h 1 is also important, and we’re well on the way to identifying the critical peptides in it, too.”

There are a few peanut therapies in the works. Is your research unique?

“There’s a lot of research in animal models [using mice], but our research looks at human white blood cells. That’s important, because peanut allergy is not a natural condition for mice.”

Next Page: More questions on the vaccine

An anaphylactic reaction includes more than one of the body’s systems, such as the respiratory tract, gastrointestinal tract, the skin and cardiovascular symptom. Symptoms of an allergic reaction include tingling in the mouth, swelling of the tongue and throat, itchy skin or hives, difficulty breathing, abdominal cramping and vomiting. In a severe anaphylactic reaction, a person may experience a drop of blood pressure, loss of consciousness and even cardiac arrest and death.

One of the issues in managing peanut allergy is that symptoms can vary. A person may have had minor symptoms, only to suffer anaphylaxis on a subsequent exposure.

Because peanut allergy reactions can be severe, it is important that a person with this allergy carry an epinephrine auto-injector (EpiPen or Twinject) with them at all times. Peanut allergy is often considered a lifelong allergy, but research has shown up to 20 per cent of children may outgrow it by the time they reach school-age.*

*Source: 2010 FA primer. JACI

Prevalence

In the United States, the rate of peanut allergy in children increased by 3.5 times from 1997 to 2008, to a rate of 1.4 per cent. In Canada, it is estimated that 1.68 per cent of children and 0.71 per cent of adults have peanut allergy.

More on Peanut Allergy Statistics

Next Page: Not a Nut!