Peanut Allergy Research Studies
New research may lead to a cure
Carly Brockman, 8, gets to enjoy her favorite dessert when she visits Duke University Medical Center in Durham, North Carolina. Each time she dips into her bowl of chocolate ice cream, she is contributing to research for peanut allergy.
Carly, who is allergic to peanut and egg, is participating in an oral immunotherapy study for peanut allergy. Study participants are given peanut flour, starting in extremely small amounts (the equivalent of 1/3000th of a peanut) that increase slowly over time. A food challange in July revealed that Carly had been getting the peanut flour during the blinded study. She continues to take 4,000 mg of peanut flour at home on a daily basis and now returns to Duke every four months for skin and blood testing.
The study, which involves participants between the ages of 1 and 16, requires multiple visits over several months. During each visit, the child is given an increased dose and then later eats that dose at home each day, says Wesley Burks, M.D., chief of the division of pediatric allergy and immunology at Duke University Medical Center.
The sweet treats, along with the study’s staff members who make it a point to get to know the children and keep them busy, make participation in the study “as pleasant as it can be,” says Carly’s mom, Laura Brockman. She notes that even her 5-year-old twins, Kendall and Luke, enjoy accompanying their sister to her appointments.
“In the beginning, I didn’t want to do it because it kind of sounded scary,” Carly says. But she changed her mind when she saw a newspaper story about another girl who was participating in a peanut study. “It’s fun. Once you get used to it, it doesn’t seem as scary.”
After joining the study in July 2007, Carly went to Duke every two weeks during the first year of her participation to have her dose of peanut flour increased. Once she finished her serving of ice cream, she remained there for two hours for close monitoring. Then she was given more peanut flour to eat every day at home where her daily dose is mixed with another chocolate treat—brownie batter. It tastes like the chocolate ice cream “but a little more gooey,” Carly says, adding that sometimes she gets too much peanut in a spoonful “so I can taste the peanut and it’s icky.”
Prevalence of Peanut Allergy
Carly was diagnosed with peanut allergy just before turning two when she ate a few peanut butter crackers at a friend’s house and began acting differently. The child, usually happy to be with her friends, crawled into her mother’s lap, not wanting to play—and then she vomited. For Carly, an antihistamine followed by close monitoring by her mom was enough to control the reaction.
But she is one of the fortunate ones. Many of the more than 3 million Americans with peanut and tree nut allergies are at risk for anaphylaxis and death from accidental ingestion.
Peanuts are the leading cause of food-induced anaphylaxis, a life-threatening allergic reaction. According to the Duke University Medical Center, close to 100 adults and children die from peanut allergy every year. The condition causes an estimated 15,000 emergency room visits annually.
The allergy appears to be increasing in prevalence. A random national telephone survey involving 4,855 households found that the number of children with peanut allergy in the United States has increased significantly, doubling from 0.4 percent in 1997 to 0.8 percent in 2002. The Food Allergy & Anaphylaxis Network (FAAN) and Mount Sinai School of Medicine in New York conducted the 2002 study, which followed a 1997 prevalence study, to see if they could prove anecdotal reports by physicians and school staffs, says FAAN founder Anne Munoz-Furlong.
“It confirmed the information we were getting from the field that more kids were being diagnosed,” Munoz-Furlong says.
While no one can say for sure why peanut allergy is on the rise, there are some theories, including the hygiene hypothesis, which points to a super-sanitized nation with cleaner houses and more vaccinations that are doing a better job of getting rid of childhood diseases. This theory contends that the immune systems of many modern American infants are under-stimulated and underdeveloped; when new foods are introduced, these immune systems over-react, causing allergic symptoms. Another theory blames the way peanuts are processed.
Amy M. Scurlock, M.D., assistant professor of pediatrics at the University of Arkansas for Medical Sciences and Arkansas Children’s Hospital in Little Rock, Arkansas, says she believes that the reason for the prevalence of peanut allergy involves a genetic predisposition and environmental exposures.
“The bottom line is that further work is needed to define the role of early peanut and other potential food allergen exposures early in life,” Scurlock says. “We really don’t know with 100 percent certainty why some people develop food allergy and others don’t.”
Quality of Life
Regardless of the reason, more than 12 million Americans are dealing with food allergies every day, including about 3 million children, according to FAAN. Burks says he tries to help families gain a healthy respect for the disease, understand the serious nature of the reaction the child could have and take appropriate precautions—without letting the allergy control their lives.
“This is something that affects the quality of life but it doesn’t have to put you in a bubble,” says Scott H. Sicherer, M.D., associate professor of pediatrics at Mount Sinai in New York and author of Understanding and Managing Your Child’s Food Allergies (Johns Hopkins Press). “There are variations of how people manage with their allergy. But I think it’s very important to try to seek out how to live life as safely as possible but still participate in everything everyone else participates in without eating the food that you are allergic to.”
Families with food-allergic children should keep their youngsters as safe as possible by strictly avoiding the allergen, having ready access to emergency medicine (e.g., epinephrine and antihistamines) and having a plan in place for anyone who takes care of their child, Scurlock says.
New research is fueling hope for treatment of food allergies, particularly the peanut allergy. Various ongoing studies aim to change a person’s immune response to peanuts, lessening the reaction to peanut exposure and possibly finding a cure for the allergy.
“We’re hopeful that over time we will actually create therapies to develop tolerance, which would change the immune response to peanut,” Scurlock says.
Burks says he believes that current research has the potential to provide the first generation of immunotherapy treatment for peanut allergy within the next five years.
“People are trying to look at treatment of peanut allergy and food allergy from a variety of different treatment modalities,” says Sicherer. “There’s more in the pipeline than ever before.”
Some of the research being conducted includes:
- Oral immunotherapy studies, like the one Carly Brockman is in, which involve having peanut-allergic children ingest peanut flour on a regular basis;
- Studies of Chinese herbal medicine to examine its therapeutic effect on food allergy;
- Development of an engineered vaccine in which peanut proteins are altered so that the vaccine can treat the allergy without causing a reaction; and
- Sublingual immunotherapy in which a liquid concentrate of peanut is placed under a study participant's tongue to lower sensitivity over time.
“Each of these is progressing,” Burks says of the current studies. “I don’t know that we can predict which one will look the best in five years but I think all of them have some promise.”
Burks, who is conducting the peanut oral immunotherapy research at Duke, says oral immunotherapy does appear to raise the threshold of the amount of peanut it takes to cause a reaction. But he stresses that the research is still investigative, not something to be tried at home or even in a physician’s office. The studies are conducted in a research setting where participants are closely monitored and emergency care is on hand.
“This treatment holds a lot of promise and we’ve been encouraged by the results,” Burks says. “But it’s not something that we would do in practice yet.”
Scurlock is involved in the oral immunotherapy research in Arkansas in collaboration with Duke. “For people who have peanut allergy, this could really be a life-changing therapy. It could cause them to be protected from accidental ingestion,” she says.
The Arkansas hospital has been involved in the study for about five years, starting with a pilot oral immunotherapy project that worked with egg allergy. That proof of concept study revealed that patients could be desensitized to egg protein, an important finding that laid the basis for similar work with peanut allergy.
Researchers are paying a bit more attention to the peanut allergen, Scurlock says, because it typically is not an allergen people outgrow and it often results in a more severe reaction than seen with other food allergens.
Mount Sinai is the lead clinical center for the Consortium of Food Allergy Research (CoFAR), which was established by the National Institute of Allergy and Infectious Diseases (NIAID) in July 2005.
One treatment option being examined at Mount Sinai is the study of a Chinese herbal remedy, stemming from research conducted by Mount Sinai researcher Xiu-Min Li, M.D. She created mice that were allergic to peanut and then she treated the mice with herbs to assess their effect on the allergy. Results of the mouse model have been promising, Sicherer says.
Mount Sinai is in the first stage of testing the Chinese herbal remedy on human subjects, conducting a safety study on people ages 12 and older with peanut, tree nut, shellfish or fish allergies. The study, which began in December 2007, involves blood testing on participants and provides the treatment for seven days. At the end of the seven days, participants are monitored and retested to see whether the herbal remedy made them sick.
Mount Sinai has also been working on a vaccine for peanut allergy with Duke for about ten years. When allergy shots for peanuts—similar to the shots given to people who are allergic to pollen— were first examined in a study, participants were able to eat more peanuts. But the shots caused side effects, including anaphylaxis, Sicherer says. Scientists at the two sites have been working on reengineering the peanut protein in a way that would teach the immune system to stop reacting to peanuts. Burks says he
is hopeful that the first human studies on the safer vaccine will begin in the next year.
All five CoFAR sites (Mount Sinai, Duke, Johns Hopkins University, National Jewish Medical and Research Center, and the University of Arkansas for Medical Sciences) are involved in a study of peanut sublingual immunotherapy, which began in April 2008. The 4-year study of 12- to 40-year-olds with peanut allergy involves putting a liquid peanut product or placebo under each participant’s tongue. The study starts with minute quantities of peanut, which are then increased over time. Researchers are measuring whether sublingual therapy will cause desensitization and eventually tolerance of the allergen.
The five CoFAR facilities are also conducting an observational study involving more than 400 children in the first few months of life who are thought to have a high likelihood of developing peanut allergy. The children have atopic dermatitis and either a milk or egg allergy. The study, which started in 2006, will follow the children for five years to discover how many eventually develop peanut allergy.
“We hope to better understand why some kids develop peanut allergy and why it goes away in some,” says Burks. “Then we’ll be able to develop better treatments.”
Study participants are key to helping scientists move the research to the next step and achieve results. But it’s not easy for people to sign up for a study that requires multiple visits and exposes them to risks, notes Sicherer. It has been challenging, for example, to find participants for the herbal remedy study, he says.
The decision to join the peanut oral immunotherapy study at Duke was difficult for Laura Brockman, Carly’s mom. She first became interested when she heard about Burks, who is conducting the peanut oral immunotherapy research at Duke.
“Dr. Burks was almost like a hero. He was so passionate about something that was important to me,” Brockman says, adding that she admired the fact that Burks considered solving the peanut allergy so critically important. “I wanted to have Carly see him as an allergist but I was also hoping to get her into the study.”
But when Brockman read in the extensive paperwork about the risks that came with research participation, reality hit home.
“It’s hard to decide to give your kid poison,” Brockman says.
Today she’s glad that she consented to have Carly participate in the research. Not only is she pleased with the extra care that study staff give her daughter, she’s also gratified to be working toward a possible solution to Carly’s allergy.
“You feel like you’re doing something,” Brockman says. “Even if it doesn’t work, at least you’re trying instead of just sitting back.”
Brockman’s advice for other parents considering enrollment in a food allergy study? Make sure you are aware of the commitment before beginning. Study participation has changed the Brockman family’s lifestyle during the past year. In addition to spending four hours every two weeks at the Duke appointment (including travel to the site near her home), timing the daily dose with other activities also takes some adjustment.
When she first enrolled, Brockman thought she would be able to give Carly the peanut flour dose with a small snack after school. That proved to be too little food, causing Carly to vomit. While Brockman was not alarmed by the vomiting (there were no other symptoms that would indicate a dangerous reaction), she also knew she needed to figure out a way to administer the dose, enough to be effective, so that Carly wouldn’t get sick. After some trial and error, she figured out a schedule. Carly eats dinner first and then takes the dose.
Brockman sticks close to Carly after she eats the peanut flour. For example, other parents drop their children off at a two-hour dance practice in the evening but Brockman stays the whole time, just in case.
Early in the study when the portions were small, Brockman mixed the peanut flour in with a little pudding. But by the time Carly had been in the study for nearly a year, the little girl was getting 3,373 mg of peanut flour, the equivalent of close to 12 peanuts. That’s when mixing the dosage into thick brownie batter worked to better mask the taste.
A Family’s Hope
Brockman’s goal for participating in the peanut research is to hasten the day when the peanut allergy can be effectively treated—and cured. Although she hopes for a major breakthrough in five years, the thought seems almost too good to be true.
“It would be wonderful if this would fix her allergy,” Brockman says. “But it still would be scary for quite a while. I can’t imagine ever totally being convinced that Carly could eat peanut butter and jelly all the time and not worry about it.”
Carly doesn’t care so much about peanut butter and jelly. She just wants to be able to enjoy the same treats as her friends at school.
“I’ll hopefully not have the allergy anymore so I’ll be able to eat the cakes and the cupcakes that people bring in,” she says. LW