Charles Jones describes his 6-year-old son's peanut allergy as "sort of a black cloud everywhere we go." Watson Jones' family never knows where peanut particles might lurk. In the scooper at the ice cream parlor? In the pesto at the pizzeria? On the monkey bars at the playground?
Watson is one of an estimated 4% of Americans — 3 million of them children — who are allergic to foods ranging from shellfish to nuts. Even a trace could trigger a lethal reaction.
STUDY: Food allergies on the rise in kids
"All other allergies have lots of treatments," says Anne Munoz-Furlong, founder of the Food Allergy & Anaphylaxis Network. "With food allergy, we have nothing: Avoid the food, take epinephrine (adrenaline shots to counteract anaphylaxis, a deadly reaction) and get to the hospital."
Accidental exposures to food allergens are common. Each year, they lead to 50,000 emergency room visits and cause at least 150 deaths in the USA, Munoz-Furlong's non-profit says. Most children outgrow milk, egg, wheat and soy allergies, but allergies to peanuts, tree nuts, fish and shellfish often are lifelong.
But now, several new potential treatments are moving from laboratory and animal testing and into clinical trials, giving patients and their families hope that they someday may subdue or even conquer food allergies.
"This is the first time that we have a number of studies going on at the same time," Munoz-Furlong says. "This is huge for the food allergy community. We finally can say that probably in 10 years, the landscape will look very different than it does now."
Scientists' primary goal is to build patients' tolerance so they won't have a life-threatening reaction. Researchers hope to persuade patients' immune systems that peanuts and other food allergens aren't serious threats.
Early results in tests on humans look promising for three experimental treatments:
•Oral immunotherapy. Under close supervision by health care professionals, patients swallow tiny but gradually increasing amounts of the foods that trigger their allergies, with the idea of building immunity. This method is being tested for peanut, egg and milk allergies.
•Sublingual therapy. Drops containing proteins that trigger allergies are put under the tongue, where they are absorbed into the bloodstream. This method is being tested for various food allergies.
•Food allergy herbal formula-2. Known as FAHF-2, this pill (not available in stores) is based on a 2,000-year-old Chinese remedy. It contains nine botanicals, including ginseng and oil made from cinnamon tree bark. It is being tested for peanut, tree nut, fish and shellfish allergies.
Building tolerance can take a year or more, and parents with children in the studies must drive them to a research center every other week. For a few, the round trip is hundreds of miles — a small price, in parents' eyes.
"They will do anything humanly possible" to overcome their children's food allergies, says Stacie Jones (no relation to Charles Jones), an Arkansas Children's Hospital allergy specialist who helps lead several trials. "It is a testament to their commitment."
Anxious kids and parents
Enrolling in clinical trials of food allergy treatments takes not only a long-term commitment but also a leap of faith. To see whether a treatment is working, scientists perform skin tests and blood tests that measure levels of antibodies produced against a specific food. But the best way to test a treatment is to give patients the foods to which they're allergic and see what happens.
"We have raised these kids saying, 'Do not ever under any circumstances let anybody give you this,' " Stacie Jones says. "Every now and then, we will have an anxious kid."
Or parent.
"The first day was horribly scary," says Melissa Bernard of Roanoke, Va. Her son, Justin, participated in a peanut oral immunotherapy study by Wesley Burks at Duke University in Durham, N.C., and Jones in Little Rock.
The Bernards discovered Justin's peanut allergy when, at 15 months, he bit into his mother's peanut butter and jelly sandwich and broke out in hives. He's also allergic to eggs.
"Our local allergist told us he may outgrow his egg allergy, but he's never going to outgrow his peanut allergy, so we'd better learn to live with it," Bernard says.
That wasn't good enough for her. She worried about Justin's safety when he entered school, surrounded by kindergartners eating peanut butter and jelly sandwiches or munching peanut-laced goodies at parties.
"I just got on the Internet one night and started putting in 'peanut allergy cure,' 'peanut allergy research,' " Bernard says. She came across a mention of Burks' study and e-mailed him.
"I'm not a risk-taker. I certainly don't take risks with my children," she says. Burks' premise "just made sense to us." Besides, "really, there was nothing else."
Justin entered the study at Duke in 2005, at age 2. The first day, he broke out in hives and struggled to breathe after swallowing less than one-tenth of the protein in a peanut kernel.
"All during this time, they're drawing up the epinephrine to give him. To us, it seemed forever," Bernard says.
She remembers thinking, "Oh my goodness. What have I done to him?" But the next day, the scientists gave Justin a pinch of peanut flour just under his allergy threshold, and he was fine.
Every other week for seven months, Bernard made the three-hour drive from Roanoke to Duke so researchers could monitor Justin's reaction to ever-increasing doses of peanut flour.
They then reduced their trips to once every four months. Researchers kept checking Justin's blood levels of immunoglobulin E, or IgE, antibodies to peanuts. People who aren't allergic don't have any. The decline in Justin's levels signaled that his immune system was beginning to regard peanuts as friend, not foe.
In January 2008, Duke scientists decided Justin was ready for his second challenge: a PB&J sandwich. If he had no reaction, he could end treatment.
"It was nerve-racking," Bernard says. "I had to walk out of the room. Here's the thing we kept him from for so long. It was kind of like giving your child poison and watching him."
Not surprisingly, Justin wasn't thrilled about it, either. The teary 5-year-old agreed to eat a sandwich only after his dad, Randy Bernard, did. Justin ate the whole thing — and nothing happened.
"He was proud of himself," says Melissa Bernard, who rewarded Justin with his first plain M&Ms (made in the same plant as peanut M&Ms, even they can trigger reactions). Justin is now enrolled in an oral immunotherapy trial for his egg allergy. For now, treated patients such as Justin must eat the equivalent of at least six peanut kernels a day to maintain their tolerance.
"He's not crazy about it," Bernard says. "He would not voluntarily eat a PB&J sandwich." Justin prefers his peanut butter with chocolate or between crackers. His mom recently bought a case of Reese's peanut butter eggs, each of which contain Justin's daily dose of peanut protein.
Says Bernard: "If I could file Reese's under my medical insurance, that would be real nice."
Justin participated in a study in which everyone got peanut flour. Now Burks and Stacie Jones are conducting a placebo-controlled randomized trial, considered the gold standard for assessing medical therapies. (Without a placebo comparison group, they can't be certain their subjects didn't simply outgrow their allergies.)
Half the participants were assigned to get peanut flour; the other half, oat flour. In this "blinded" study, neither the scientists nor the subjects know who's getting which flour.
After a year of treatment, all are being challenged with tiny, escalating doses of both flours. Because no one knows who got which treatment, all participants have an intravenous line in place in case they quickly need fluids or medication.
"We're prepared as best we can and watch them real close," says nurse practitioner Pam Steele, who works with the Duke researchers. Those who had been on the oat flour have a reaction to peanut flour much sooner than the others, unblinding the study. Then, those who had been swallowing oat flour can switch to peanut flour.
Watson Jones entered the study last Memorial Day, so his family doesn't yet know whether he has been getting oat or peanut flour. On Monday, the Duke researchers will increase Watson's dose for the final time. If he's in the peanut flour group, it will be the equivalent of 14 or 15 peanut kernels. Four weeks later, Watson will return for a food challenge, after which he'll learn which group he's in.
"Both my wife and I are foodies," says dad Charles Jones, a freelance videographer who dreams of traveling to Asia and not having to worry about whether dishes from local market stalls contain peanuts. "I'd love to share that with him, and I'd love to do it when he's still a kid, not in high school."
Betsy Talbot wants to rid her son, Bo, 7, of his peanut allergy so bad that last year she drove 26,000 miles so he could participate in the randomized trial of oral immunotherapy in Little Rock, 400 miles from the family's home near New Orleans.
"If I have a chance for my son to be able to eat birthday cake or go out to dinner, I'll do it," says Talbot, who writes a blog called Ask About My Peanut Allergy.
At the end of Bo's stint in the trial last June, the Talbots learned he had been getting oat flour. Talbot is sanguine about it. "I knew from the onset it was a possibility," she says, figuring Bo's participation will help "all the other kids out there that have this."
She's continued to drive Bo to Little Rock every other week, this time for the peanut flour treatment. He's now consuming a daily dose of peanut flour equivalent to 15 peanuts. On May 4, he'll be "converted" from peanut flour to real food containing peanuts.
And how are the Talbots — whose restaurant choices have been limited to a few fast-food chains — going to celebrate when school's out in June? They're going to Disneyland.
Under-the-tongue therapy
A slightly different approach to treating food allergies, being tested in two different trials, involves sublingual — or beneath the tongue — immunotherapy.
The treatment uses proteins that trigger food allergies, just as allergy shots use proteins that trigger inhaled allergies. Scientists tested food allergy shots in the early 1990s, Burks says. They worked for some but caused serious reactions in others.
Duke and Arkansas Children's are part of a network of five research centers enrolling patients in a trial of sublingual immunotherapy for peanut allergy. Duke and Baltimore's Johns Hopkins University also are testing the treatment for milk allergy.
Ear, nose and throat resident Kevin Lollar is leading a trial of sublingual immunotherapy for food allergies at the University of Missouri. Not approved in the USA, the treatment has been used for more than a decade in Europe for inhaled allergies and "shown to be much safer than shots," Lollar says.
He explains: Immunotherapies taken by mouth are more gradually absorbed than traditional allergy shots, greatly lowering the risk of a deadly reaction.
Unlike the other experimental therapies, food allergy herbal formula-2, or FAFH-2, does not contain food allergens. It's a modified combination of botanicals found in an ancient Chinese remedy, says pediatrician Xiu-Min Li, who's leading a government-funded trial at Mount Sinai School of Medicine in New York.
Li's lab developed FAFH-2 after a decade of testing Chinese herbs for anti-allergy properties. In mice allergic to peanuts, "this formula can produce a very long protection, although not a cure, yet," Li says. She is now studying FAFH-2 in 18 patients and plans to conduct a trial in 60.
Safe and effective treatments will come none too soon for allergy patients and their families.
"With most parents, when your child says they don't feel well, you are calm and you say, 'Tell me how you feel,' " Munoz-Furlong says.
But if your child has a food allergy, she says, "your heart stops. That's an awful way to live."
0 Comments:
Post a Comment