Peanut Allergy: Making It ‘Go Away’
Nine-year-old Isabella Uknis can do something her parents were told was impossible: she can eat half a peanut every day.
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.
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