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

Peanut allergies are severe, often affecting children, and are increasing in prevalence. It’s no wonder researchers around the globe are looking at new, inventive ideas for how “cure” them, or at the very least, how to allow those with peanut allergies to tolerate at least a small amount of this legume’s protein.

Allergic Living looks at two of the latest ideas in the labs:

Peanut Allergy Vaccine

Researchers at Mount Sinai and Johns Hopkins University are studying a vaccine for peanut allergies to see if it is safe. The vaccine contains an altered peanut protein to “trick” the immune system. Dr. Scott Sicherer, an associate professor of pediatrics at the Mount Sinai School of Medicine in New York likens the changed peanut to a baby bracelet that spells “peanut.”

“If you altered that bracelet a little bit, let’s say you changed the ‘A’ in peanut to a ‘D’, then it would say PEDNUT instead of PEANUT,” he says.

The idea is that the person’s immune system won’t recognize “pednut” and won’t mount an allergic reaction to it. However over time, if it sees “pednut” enough, it may learn to tolerate “peanut.”

Once the safety trials for the vaccine, which is administered rectally as a suppository and also contains heat-killed E. coli, are complete, researchers will begin to study if it actually reduces peanut allergy in humans.

The Desensitizing ‘Peanut Patch’

Researchers are also looking at the possibility of desensitizing people with peanut allergies through the skin.

Dr. Hugh Sampson, head of the Consortium of Food Allergy Research in the United States, told Allergic Living magazine that U.S. researchers got the idea from French research, in which scientists have developed immunotherapy patches for cow’s milk allergy.

Those researchers placed a milk-containing patch on dairy-allergic patients every other day for three months. The results were that the patients were able to consume, on average, 12 times more milk without a reaction than they could before the treatment.

• Vaccine Quest : Peanut-allergy research explored.
• Environmental Allergies : Breathing easier this spring.
• Happy Campers : Finding a good camp for an allergic kid.
• Sulphites Cook Up Trouble : The additive that sparks anaphylaxis.
• A Kiss is Not Just a Kiss : Tips for dating with allergies.
• Sabrina’s Law : Tragedy inspires a law to protect anaphylactic students.
• Ask The Allergists: About travel, pets and hidden wheat.
• Nutrition : The milk-free diet.
• Natural Beauty : The sun and sensitive skin; the best spring products.
• Food: Delectable entrées, superb salads.
• Plus: Safe restaurants; cool products; the hypoallergenic cat.

BUY THIS ISSUE

Since she had an anaphylactic reaction to a peanut butter cracker at the age of 2, Isabella has been avoiding peanut. But that all changed when her mother, Kathy, saw a report on “Good Morning America” last summer. It was about a team of researchers at Duke University in North Carolina who are trying to desensitize children with allergies to egg and peanut.

The Uknises had seen many doctors who told them there was nothing they could do; Isabella would have to avoid peanut for life. But the doctor and nurse couple always thought desensitization should, in theory, work. They called the university, and before long Isabella was accepted into the study under Dr. Wesley Burks.

Burks and his team at Duke first examined egg allergy and desensitization in a pilot study with seven participants. Over a two-year study period, and working in tiny, sequential increases of egg exposure, four of the children built up enough tolerance to eat two scrambled eggs without a reaction. The others were able to eat just under that amount.

The peanut study, which began three years ago, has 25 children enrolled at various stages. Eight have finished the first phase. After 18 months of being “on peanut,” seven of those eight were able to eat 15 peanuts over the course of an hour. They are now on a higher maintenance dose and will stay on that for more testing.

Isabella began the study last August. The nurses at Duke start by feeding her a minuscule amount of peanut powder, the equivalent of 1/3000th of a peanut, and slowly increased the dose over the course of one day, carefully monitoring her for reactions. The goal was to eat a cumulative 50 mg of peanut powder, the equivalent of 1⁄6th of a peanut.

“She didn’t do as well as we had hoped,” says her mother. At one point Isabella got a belly ache, then her nose started running and eventually, she broke out in hives, ending the day. All told, Isabella ate 25 mg of peanut. “I was really scared,” says Kathy, “I’d seen her go into anaphylaxis before.” The life-threatening potential of allergic reactions hits home for this family. In fact, the night before Isabella anaphylaxed after eating the peanut butter cracker, her father, a transplant surgeon, had done a procurement on a 21-year-old who had died of an allergic reaction.

But at the clinic, when Isabella felt symptoms the nurses treated them with Benadryl, or waited for them to subside before giving her another dose. Their knowledge, and the attention they gave to Isabella, put Kathy at ease. According to Burks, two participants weren’t able to tolerate the buildup phase, and were dropped from the study. But Isabella’s results were good enough to keep going.

After determining each child’s individual tolerance over a day, Burks and his team send them home on a maintenance dose of peanut, which they eat every day for two weeks. Then they return to the research unit for a higher dose, and are watched a few hours to make sure they’re not reacting. The kids being tested go about their regular day but, of course, take all the normal precautions, such as having an EpiPen handy. If a child has a reaction of any significance while taking the dose at home, he or she goes into the research clinic the next day and takes their next dose under the watchful eye of the clinic’s nurses.

The goal of the study is twofold. “We’re trying to desensitize them,” Burks says. “That means that if they’re on the treatment and had an accidental exposure, they would not have symptoms.” But Burks wants to go beyond desensitization, and hopes to make previously allergic people tolerant, even after they’re finished with the treatment. “We will essentially have made [the allergy] go away.”

The allergist hopes to have published results from the peanut study by mid-2007, but the early indications show that desensitization is possible. He acknowledges that proving the ‘tolerating’ part will take a little longer. But a new study, with different doses and lengths of treatment, has already begun.

Burks sees a treatment evolving in the next three to five years. He hopes that at that point, allergists could administer this “oral immunotherapy” to their patients in their offices. Although yet to be studied, Burks believes the treatment would work in adults as well as kids, and for food allergens other than peanut and egg.

Naturally, there is great interest and demand for this type of treatment. Burks has a long waiting list of local parents who want their children enrolled in the studies, in the hope that one day they will be desensitized. For the Uknises and Isabella, that once unreachable goal seems within grasp. Now it’s a matter of wait-and-see: will Isabella be one of the lucky ones?

Excerpted from the Spring 2007 issue of Allergic Living magazine.
To order that issue or to subscribe, click here.

To comment on this article, write to: editor@allergicliving.com

Recent studies of oral food desensitization suggest exciting possibilities for the 1.2 million Canadians with severe food allergies. Canadian families, particularly those families with young children living with food allergies, are understandably hopeful of medical advancements that could reduce the risk of a life threatening allergic reaction.

It is important, however, to keep the results from studies recently cited in the media in perspective. These are early days. No universal “cure” has been found. The number of study participants has been small, patients have been carefully selected, and the environments in which the studies were conducted have been very controlled.

The CSACI believes that decisions that affect public health must be evidence-based, as all good science is. There is not yet enough evidence to provide us with the information necessary to develop definitive guidelines for the public. As allergists in Canada and around the world continue to gain experience with this procedure both through research and in their own practices, the body of evidence will become greater and so too will our collective understanding of what this may mean for food allergic individuals.

In the interim, we urge families to NOT try oral desensitization for food allergies on their own. Instead, they should contact their allergist to discuss the benefits and risks of such an undertaking. Oral desensitization should only be conducted on appropriately chosen patients under the supervision and guidance of a trained and accredited allergist.

We further urge allergic individuals to continue to follow their usual safety strategies, including the individualized management plan they have developed with their allergist.

For full story Tolerating Peanut, about peanut oral immune therapy, see Summer 2009 issue.
To subscribe or order a back issue, click here.

See Also:

• Making Peanut Allergy “Go Away“
• Canadian Peanut and Nut Allergy Statistics

Ahmedna has spent the last six years developing processes and by-products from peanuts, such as a meat substitute and antioxidants from red peanut skins. But with every new product, “the issue of allergy always came into play,” he says. He set out to find a way to reduce the allergenicity of peanuts.

While some scientists are working to create peanut plants without allergenic proteins, Ahmedna developed a process that’s supposed to deactivate a peanut’s allergenicity after it’s been harvested. Neither he nor his colleague, Doug Speight of the university’s technology transfer office, will go into detail about the deactivation process, as it is proprietary information.

However, Speight suggested it could be incorporated at the wholesale level, or perhaps used at the product stage “whether a candy bar manufacturer, or a salted or roasted nut manufacturer.”

Yet Ahmedna says it’s too soon to talk of how it could be used and by whom; his so-called safe peanut still has a lot to prove. The “deactivated” legumes are just starting to be tested on humans in clinical trials. So far, the researcher and his university say his lab tests, which use human serum from severely allergic individuals showed a 100 per cent reduction in allergenicity.

But the medical advisory board of the Food Allergy & Anaphylaxis Network issued a statement questioning such results, noting that another account said the process had only reduced peanut allergenicity by 60 to 70 per cent. If so, that would fall well short of the standard of allergy-free. The medical experts also expressed concern about the storm of media coverage that followed the university’s announcement in July that it had developed “a simple process to make allergen-free peanuts.”

Dr. Scott Sicherer, an allergist with the Mount Sinai School of Medicine who sits on FAAN’s medical board, says the reason for his skepticism is simple: “There have been no data presented, or peer-reviewed, on the process or testing. From knowledge of how peanut proteins behave and how people who are allergic to them may react, it seems remarkable that it would be completely successful.”

In Canada, Chantal De Montigny, manager of scientific information at Quebec’s AQAA (Association Québécoise des Allergies Alimentaires), notes that, even if the process is proven successful, it simply raises many questions. “Is everybody around the world going to use this process?” She adds that it would be extremely important for non-allergenic peanuts to be labeled properly, perhaps even with a different name, and a picture to identify them.

Everyone from the researchers to the allergy groups is urging the peanut-allergic not to get their hopes up – just yet. FAAN’s medical board notes: “We all hope for a cure for food allergies and are excited about the interest from the scientific community.” However, “this announcement appears to be premature.”

First published in Allergic Living magazine.
To subscribe or order a single issue, click here.

(c) Copyright AGW Publishing Inc.