US: New strategies help build immunity against food allergies
Posted: April 23rd, 2009 - 2:59am
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.
"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."