HealtyDayS

Summer Allergy Relief

The good news for allergy sufferers is that springtime mountain cedars and tree pollens have generally subsided.

The bad news: It’s summertime.

“For summer, it will be grass pollen along with high ozone levels combining for a one-two punch,” said Dr. David Khan, associate professor of internal medicine at UT Southwestern Medical Center. “In July, cedar elm will appear.”

While heat doesn’t influence the amount of pollen in the air, it does aid in the formation of ground-level ozone, which, in turn, can exacerbate allergy symptoms.

To cope, Dr. Khan, who also directs the asthma clinic at Parkland Memorial Hospital, offers these tips:

• Limit outdoor exposure during peak times - from mid-morning to midday.

• Air-conditioning filters out some allergens. Keeping windows closed lessens the amount of allergens that travel into the home.

• If you’re out for long periods during the day, take a shower before bedtime to wash off some of the allergens and prevent them from being transferred to pillows. “Your hair can be like a pollen magnet,” warns Dr. Khan.

• Wear a mask while mowing the lawn or doing yard work.

• Take allergy medications before you go outside, so they have time to work into your system.

Choosing the right medications to help control symptoms is important, Dr. Khan said. Antihistamines are the most common medications used for allergies. They can help relieve itching, sneezing and runny noses, but don’t generally help with stuffiness.  Oral decongestants like pseudoephedrine generally work for stuffy noses.

Topical decongestants - nose sprays - aren’t a good long-term solution because you can become addicted to them, causing nasal passages to swell even more and possibly resulting in other nasal problems as well.

If symptoms aren’t subdued or allergies are interfering with your lifestyle or work, it’s probably a good time to find an allergy specialist and see if other treatments may help.

“It’s reasonable to try some of the over-the-counter drugs first, and if you’re not satisfied with those results, then you need to see a doctor,” Dr. Khan said.

At UT Southwestern, patients can be evaluated by UT Southwestern allergists in clinics at the James W. Aston Ambulatory Care Center, Parkland Memorial Hospital and Children’s Medical Center Dallas, where doctors treat airborne and environmental allergies or asthma, food and drug allergies, and conditions like hives and allergic reactions.

Prescription antihistamines can offer more potency and be less sedating than over-the-counter measures, Dr. Khan said.

Corticosteroid anti-inflammatory nasal sprays can be used regularly, often once a day, and are generally safe and effective. These are not the same as anabolic steroids that athletes sometimes abuse and for which some school systems now test.

Antihistamines, decongestants and corticosteroids, however, do no more than depress symptoms. “Although you’ll be reducing the effect of the allergic reaction, you’ll still be just as allergic at the end of the day,” Dr. Khan said.

Shots are the most effective medical treatment, he said, actually making allergy sufferers less allergic.

There’s also a novel clinical approach, called rush immunotherapy, which simply means taking more shots over a shorter period of time. Doctors think this may help expedite results.

Penaut Allergy

About 20 percent of babies with eczema or milk and egg allergies will develop an allergy to peanuts by age five, studies show. Duke University Medical Center researchers are now enrolling infants into a trial to study how and when peanut allergies arise in children.

Most children sensitive to peanuts experience their first allergic reaction between 14 and 24 months of age, often at the time of first exposure. These allergic reactions are potentially life-threatening, even the first time. Some children react to as little as 1/1000th of a peanut. The number of children with peanut allergy has doubled in the U.S. between 1998 and 2003. If signs of allergy, such as eczema, appear before six months of age, there is a one in five chance a child will develop peanut allergy by age five.

“Parents are increasingly concerned as they hear more about peanut allergies. They want to know what they can do to prevent their children from developing a peanut allergy,” said Wesley Burks, M.D., chief of the division of pediatric allergy and immunology at Duke.

Burks and his colleagues will track 400 children for five years to better understand the development of peanut allergies. In partnership with the child’s family physician, the researchers will watch for signs of peanut allergy, periodically collect blood samples and search for genes that influence peanut allergy. The team will also examine potential environmental factors affecting allergy.

“We hope that by better understanding when peanut allergies develop, we can offer improved treatment and prevention strategies for children,” Burks said. The study may also help physicians predict which patients with peanut allergy are most at risk for a recurrence of severe allergic reactions after first exposure to peanuts.

Despite their best efforts, many people with peanut allergy will accidentally ingest peanut products. Signs of an allergic reaction to peanuts in young children include skin, respiratory and gastrointestinal symptoms: hives, an itchy rash, wheezing, throat tightening, vomiting or diarrhea. Peanuts are the leading cause of food-induced anaphylaxis, a life-threatening reaction that constricts the airway and lungs, severely lowers blood pressure and causes swelling of the tongue and throat. Nearly 100 adults and children die from allergic reaction to peanuts each year, and the allergy causes as estimated 15,000 emergency room visits yearly. The only treatment once symptoms appear is taking an antihistamine, and then epinephrine, to relieve shortness of breath.

The trial is funded by the National Institute of Allergy and Infectious Diseases, through a grant to the Consortium of Food Allergy Research (CoFar). Other CoFar institutions enrolling children in the trial include Mount Sinai Medical Center, Johns Hopkins University, National Jewish Medical and Research Center, University of Arkansas for Medical Sciences and Yale School of Medicine.

Burks is also studying a possible new method for fighting peanut allergy in children. “What we’re doing is to take small amounts of peanut protein and gradually giving increasing amounts over an initial day and then over a period of three-and-a-half to four months. Every other week, we give them a larger dose,” explains Burks. “At the end of that period, they’re getting about 300 milligrams of peanut protein, which is the equivalent of one peanut.”

“What we’re finding is that they’re less sensitive when they eat a peanut accidentally, so that they’re not having the same reaction they did before,” Burks said. “We hope by the end of this study they’ve actually ‘outgrown’ their peanut allergy.”

Allergy Drug

Researchers, working with colleagues at St George’s, University of London, are developing drugs designed to stop allergens from entering the body, so rendering them harmless.

Professor David Garrod said the research – recently shortlisted for the Northwest Regional Development Agency’s Bionow Project of the Year – takes a completely new approach to the treatment and prevention of allergies.

“The technology is based on our earlier discovery of how allergens, the substances that cause allergy, enter the body through the surface layer of cells that protect the skin and the tubes of the lungs,” he said.

“Allergens from pollen or house dust mites are inhaled and then dissolve the binding material between the cells that form these protective linings; they can then enter the body by passing between the cells to cause an allergic response.

“The drugs we are developing - called Allergen Delivery Inhibitors (ADIs) – are designed to disable these allergens so they can no longer eat through the protective cell layer and block the allergic reaction before it occurs.

“The effect will be like avoiding allergens altogether. Removing carpets and rigorous cleaning of homes are established ways to avoid allergens, but they are only partially effective because their effects do not ‘travel’ with allergy sufferers.

“ADIs promise to be significantly better because taking a medicine is easier than rigorous housework and pills are portable.”

Professor Garrod, who is based within Manchester’s Faculty of Life Sciences, said work on the first ADI chemical was well advanced and potential drugs could enter clinical trials as early as 2010.

If successful, the drug would treat established symptoms already found in adult sufferers and, in due course, could be used to prevent allergies in children.

“Prevention of allergies has never before been possible,” said Professor Garrod. “Current medicines don’t act against the allergen at this early stage – they only ease the symptoms – so the development of these ADIs would be a major breakthrough in our fight against allergies.”

Food Allergy

Researchers have identified one of the proteins that may be responsible for causing food allergies, which could lead to the development of more accurate non-invasive tests to identify true food allergies, according to a study published in the July issue of Gastroenterology, the journal for the members of the American Gastroenterological Association.

Food allergies often present a unique problem for allergy testing since not every patient has detectable levels of immunoglobulin E (IgE) in their serum, especially patients with delayed allergies. A number of reliable testing methods exist for food and other allergies, including skin tests and serum IgE tests, however, they may not accurately diagnose food allergies. The oral food challenge is considered the most accurate test for food allergies but is expensive to administer and has to be done in a controlled environment. Immunoglobulin (antibody) E is a protein produced by plasma cells (or B-Cells , a type of lymphocyte ), which is designed to control the immune response in extracellular fluids by binding to substances in the body that are recognized as foreign.

The study, conducted at the Mount Sinai School of Medicine, New York, showed for the first time that CD23, a protein normally expressed in a person’s intestinal tract, acts as a receptor for IgE, a protein associated with allergic reactions, and enables it to participate in food-allergic reactions.

“We believe that the presence of CD23 may provide a surrogate method of looking at the gut without invasive tests like biopsies,” according to M. Cecilia Berin, PhD, assistant professor, pediatrics/allergy and immunology, Mount Sinai and lead author of the study.

Results of this study showed that CD23 was detectable in stool samples from food allergic patients, but not the controls, suggesting either increased levels of CD23 on intestinal cells or an allergen-induced shedding of CD23 in food allergic patients. Additionally, researchers found a strong correlation between the level of CD23 and food-specific IgE in the stool, demonstrated by the availability of IgE antibodies to interact with CD23 on the outside surface of the gastrointestinal wall.

Researchers collected stool samples from nine pediatric patients (age range three to 17 years) who underwent an oral food challenge, during which they were administered either egg or milk in a controlled environment. All patients had a history of allergies to these foods and had reacted positively through other testing methods. Their symptoms, which occurred less than two hours after the food challenge, included skin reactions, breathing problems and gastrointestinal problems or a combination. They were matched to five pediatric controls with no food allergies.

“Based on the results of our study, we intend to conduct larger scale trials of patients with food allergic disorder to determine how CD23 in the stool correlates with clinical findings,” according to Dr. Berin. “We hope to determine that CD23 offers a promising target for food allergies that leads to more accurate, easier to tolerate tests for these patients.”

Food allergies affect an estimated six to eight percent of American children age four years or younger and approximately two percent of adults, according to the National Institute of Allergy and Infectious Diseases (NIAID). The study authors estimate that three and a half to four percent of these food allergies are IgE-mediated. While many people believe they have food allergies, the majority of individuals experience food intolerance.

Food allergies are an exaggerated immune response in which the body produces histamines and antibodies that induce symptoms in the gastrointestinal tract, airways and skin, and in the most severe cases induces anaphylactic shock, an often fatal systemic reaction. These allergies are often characterized by abdominal pain, diarrhea, vomiting, hives, swelling of the eyelids, face, lips and tongue, shortness of breath or wheezing and difficulty swallowing, among other symptoms. The most common allergens are peanuts, tree nuts, shellfish, fish, wheat, milk, eggs and soy.

Food Allergy

As children head back to the classroom, Health Canada is reminding parents of the importance of allergy awareness when packing lunches for their children. Severe allergic reactions can occur quickly and without warning, and some foods, like peanuts, can be life-threatening to allergic children.

As many as 1.2 million Canadians may be affected by life-threatening allergies and these numbers are increasing, especially among children. Foods account for most children’s allergies, with peanuts, tree nuts, sesame, soy, fish and seafood, wheat, eggs and milk being the most common food allergens.

When someone ingests even a tiny amount of an allergen, the symptoms of a reaction may develop quickly and can become very serious. The most dangerous symptoms include breathing difficulties, a drop in blood pressure or shock, which may result in loss of consciousness and even death.

Because of this, many elementary schools are now restricting certain foods from student’s lunches. Parents are encouraged to follow school policies, even if their child is not allergic. To find out which foods, if any, are restricted in their children’s schools, parents should contact the school directly.

There is no cure for food allergies. The only option is complete avoidance of the particular allergen. This is why it is important that allergic children not be exposed to allergens that regularly cause extreme and sometimes fatal reactions.

Health Canada has a number of food allergy factsheets which provide information on the nine priority food allergens. An It’s Your Health article is also available that provides additional information on severe allergic reactions.

A New Allergy Treatment

The New England Journal of Medicine today reported that a new approach to allergy therapy not only reduced the acute allergic responses of individuals with ragweed allergies but also sustained that effect for over 12 months. The novel treatment, called “AIC” in the paper, is a TLR9 agonist linked to ragweed allergen, developed by Dynavax Technologies Corporation.

Dr. Peter Creticos, principal investigator and lead author of the paper, entitled, “Immunotherapy with a Ragweed-Toll-like Receptor 9 Agonist Vaccine for Allergic Rhinitis,” said that the pilot study “appears to offer a means of achieving long-term clinical efficacy in ragweed allergic rhinitis as the clinical effects suggest the induction of long-lasting disease modification. Furthermore, the demonstrated therapeutic properties and safety pave the way for a therapeutic intervention that is qualitatively superior to standard immunotherapy.” Dr. Creticos is Associate Professor of Medicine and Clinical Director of the Division of Clinical Immunology of The Johns Hopkins University School of Medicine. He serves as Medical Director of the Johns Hopkins Asthma and Allergy Center in Baltimore, Maryland.

In the paper, Dr. Creticos pointed to statistically significant efficacy results including peak Nasal Symptom Complex Score (NSCS) reductions in AIC-treated patients of 55% (p=0.03) in 2001 which persisted through the 2002 ragweed season (53% reduction in NSCS, p=0.02) with no additional therapy. Additionally, the AIC-treated group used no relief medication at all during the second season, while placebo patients used antihistamines for 8 days (average) and decongestants for 4 days (average) of the two-week peak season. The intervention also generated clinically significant quality of life improvements for patients. Dr. Creticos added that the intervention was safely tolerated as no treatment-associated serious adverse reactions were reported, nor did any lab tests show abnormalities in the patients tested.

With funding from the National Institute of Allergy and Infectious Diseases and the Immune Tolerance Network, and the study drug provided by Dynavax, Dr. Creticos conducted a blinded, randomized, placebo-controlled, clinical trial in 25 ragweed allergic patients beginning in May 2001 and concluding in October, 2002. Patients were treated with either the drug or placebo, using a 6-injection regimen, prior to the first ragweed season, and were followed for two years. Dynavax supplied the study drug, now known as TOLAMBA(TM), and contributed to trial design, but did not participate in data accrual, analysis, or funding of the trial. TOLAMBA, consisting of a TLR9 agonist linked to a specific ragweed allergen, is currently being evaluated in late-stage clinical trials for the treatment of allergic rhinitis.

DYNAVAX Clinical Trials Update

In the paper, Dr. Creticos recommends additional large-scale studies, which are now underway at Dynavax. Since the reported study’s initiation in 2001, Dynavax has generated a substantial amount of data in 14 clinical trials in the U.S., France, and Canada. More than 7,000 TOLAMBA injections have been administered to over 1,100 patients. In these trials, TOLAMBA was shown to be safe and well tolerated, to provide measurable improvements in allergy symptoms, and to reduce medication use.

TOLAMBA consists of 1018 ISS, a TLR9 agonist, linked to the purified major allergen of ragweed, called Amb a 1. The linking of ISS to Amb a 1 ensures that both ISS and ragweed allergen are presented simultaneously to the same immune cells, producing a highly specific and potent effect suppressing the Th2 cells responsible for inflammation associated with ragweed allergy. Moreover, this treatment reprograms the immune response away from the Th2 response and toward a Th1 memory response so that, upon subsequent natural exposure to the ragweed allergen, long-term protection is achieved.

Other Clinical Results; Trial Background

A Dynavax-funded, 30-center, placebo-controlled study in 738 ragweed allergic subjects, aged 18 to 55 years, is expected to produce interim data at one-year in the first quarter of 2007. The study known as “DARTT” (Dynavax Allergic Rhinitis TOLAMBA Trial) randomized subjects into three arms: the same dosing regimen that was used in the completed Phase 2/3 trial; a higher total dose regimen; and placebo. Subjects received six doses over six weeks prior to the start of the 2006 ragweed season. Ragweed symptoms were followed over the 2006 ragweed season and will also be followed through the 2007 season. The primary endpoint is reduction in total nasal symptom scores (TNSS) during the second (2007) peak ragweed season. Dynavax anticipates that data from the DARTT interim analysis, if positive, combined with the safety and efficacy data from the recently completed two-year Phase 2/3 trial, and from an ongoing trial in ragweed allergic children, could provide sufficient patient data for determining the potential timeline to registration for the intervention.

Additionally, Dynavax is evaluating TOLAMBA in a three-year, 19-center, pediatric trial with over 300 patients, ages six to 15 years. The primary endpoint of the study is reduction in TNSS during the 2006 peak ragweed season; a key secondary endpoint is the prevention of progression to asthma. The study was initiated in early 2005. Primary endpoint data for the study is expected in early 2007.

In January 2006, Dynavax announced that results from a two-year Phase 2/3 clinical trial of TOLAMBA showed that patients treated with TOLAMBA experienced a statistically significant 28.5% reduction in total nasal symptom scores (TNSS) compared to placebo-treated patients in the second year of the trial (p=0.024). Results also showed significant clinical benefit relative to secondary endpoints, including composite hay fever symptoms and ocular effects, and a significant reduction in antihistamine use (p=0.01). These results were achieved after a single short course of therapy prior to the first ragweed season (2004), and demonstrated that a booster dose prior to the second season (2005) was not required to achieve clinical benefit. The safety profile of TOLAMBA was favorable; systemic side effects were indistinguishable from placebo and local injection site tenderness was minor and transient.

TOLAMBA represents the foundation of a comprehensive allergy franchise for Dynavax, and has the potential to be a novel entrant in the multibillion- dollar global allergy market. In the U.S. alone, approximately 40 million people suffer from allergic rhinitis. Ragweed is the single most common seasonal allergen, affecting up to 75% of those with allergic rhinitis, or 30 million Americans. Current therapeutic options are mainly limited to symptomatic therapies and conventional allergy immunotherapy, which generally requires 60-90 shots over three to five years and represents a significant treatment burden for allergy sufferers. Dynavax believes that TOLAMBA has the potential to become the first of several new and important disease-modifying therapeutic options for patients and physicians.

 Hay Fever Treatment Through Allergy Vaccine

Researchers at The Johns Hopkins University School of Medicine have successfully used an experimental DNA-based vaccine to protect against ragweed allergies, commonly known as hay fever, after just six injections. Patients receiving the vaccine showed an average 60 percent reduction in allergy symptoms compared to those receiving a placebo.

The experimental therapy holds the promise of one day eliminating the need for traditional allergy medicines targeting allergy symptoms, such as nasal steroids and antihistamines, and providing a safer, faster replacement for immunotherapy regimens, which are costly and take years to work, the researchers say.

The Hopkins study, conducted during two fall ragweed (”hay fever” ) seasons in Baltimore, Md., enrolled 25 volunteers, ages 23 to 60, with a demonstrated history of ragweed allergy. Fourteen people received the vaccine, administered as six weekly shots, while 11 others received placebo injections.

During the test period, allergic symptoms were monitored and recorded, right down to how often volunteers’ noses ran and how many times they sneezed. Compared to the placebo group, those who received the vaccine exhibited a 60 percent reduction in all of their allergy symptoms, including sneezing, runny nose, watery eyes and itching.

Relief from allergic symptoms was as pronounced in the second year as in the first, even though no more vaccine was administered. Lead investigator Peter Creticos, M.D., medical director of the Johns Hopkins Asthma and Allergy Center in Baltimore, explained that such prolonged relief is an important part of his team’s findings because it appears that the vaccine’s efficacy doesn’t wear off quickly. A new study, currently under way, will further examine the drug’s lasting effects in a larger group of participants.

Creticos’ current findings are published in the Oct. 5 issue of the New England Journal of Medicine.

“This therapeutic intervention heralds a major advance in the treatment of allergic rhinitis,” says Creticos. “Long-lasting relief can be achieved with a concise, six-week injection regimen, as opposed to the current, tedious, four- to five-year course of treatment with allergen immunotherapy.”

Investigators at the University of California, San Diego (UCSD) had previously observed that a particular sequence of DNA, derived from bacteria, shuts down a T-helper cell (Th2) involved in the body’s inflammatory response. Creticos and his team, recognizing that allergic disease is driven by Th2 inflammation, then embarked on a series of studies to evaluate the effectiveness of using this approach to treat allergies. The central question that they sought to answer was, What would happen if the DNA strand was linked to the most allergenic portion of the ragweed pollen protein, which is the number one cause of seasonal allergies in North America?

Dynavax Technologies Corp., of Berkeley, Calif., developed the vaccine and funded several of Creticos’ early safety studies. Creticos was a paid consultant of Dynavax during that period. The current study was sponsored by the Immune Tolerance Network, which receives its funding from the National Institute of Allergy and Infectious Diseases and the National Institute of Diabetes and Digestive and Kidney Diseases.

Creticos explained that the vaccine works in two ways: by suppressing acute allergic reactions (like sneezing) and by helping the body better regulate chronic inflammation (like itchy eyes and a runny nose).

It is thought that the vaccine lessens the immune system’s excessive reactions to inhaled allergens by stimulating protective cells that turn off the Th2 helper cells. The TH2 helper cells send out signals for the body to create more IgE, the protein largely responsible for making allergy sufferers miserable throughout the entire ragweed season. Someone allergic to ragweed has inherited the ability to make too much IgE antibody when exposed to inhaled allergens.

Additionally, the allergy vaccine may activate specialized immune cells known as “dendritic cells” that serve as peacekeepers, maintaining balance by keeping inflammation in check over the long term and breaking an otherwise self-sustaining allergic cycle Creticos calls “Th2 orchestrated allergic inflammation.”

“We are turning off an inappropriate or abnormal allergic response and returning the body to normalcy,” says Creticos. “Our hope is that we can one day provide a long-term cure for hay fever and other chronic inflammatory diseases.”

Allergy in Children

Infants whose parents have allergies that produce symptoms like wheezing,  asthma, hay fever or hives risk developing allergic sensitization much earlier in life than previously reported, according to a study by Cincinnati researchers.

The study suggests that the current practice of avoiding skin testing for airborne allergens before age 4 or 5 should be reconsidered, so children in this high-risk group can be detected early and monitored for the possibility of later allergic respiratory disease.

Produced by scientists in UC’s departments of environmental health and internal medicine and at Cincinnati Children’s Hospital Medical Center, the study is reported in the October 2006 edition of The Journal of Pediatrics.

The Cincinnati researchers collected data on 680 children being evaluated for enrollment in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), sponsored by the National Institute of Environmental Health Sciences (NIEHS), and compared their results with findings in a 2004 Swedish study.

Using the skin-prick allergy test, the Swedish group found that in their general population - which included children whose parents did not suffer from allergies - 7 percent had allergic sensitivity at age 1. The Swedes tested five allergens, two of which were food allergens.

The Cincinnati results, however, showed that 28.4 percent of infants born to “atopic” parents, defined as those with allergies, were sensitized to one or more airborne or food allergens. Eighteen percent were positive to one or more airborne allergens, and 13.7 percent were positive only to an airborne allergen.

According to UC epidemiologist Grace LeMasters, PhD, principal investigator for CCAAPS and the lead author of the report, the Cincinnati findings suggest that the potential for allergic disorders in infancy is underemphasized, “even though sensitization to allergens at younger ages has been shown to be more important than sensitization in late childhood for the development of wheezing symptoms and asthma.”

Food Allergy Relief With Alcoholic Milk?

Feeding babies alcoholic milk may help to protect against some food allergies. Kefir, a traditional fermented drink, is consumed in Eastern Europe as a health food, and is often used to wean babies, as it is easily digested. Food allergy prevalence is especially high in children under the age of three, with around 5-8% of infants at risk. Currently the only treatment is avoidance of the problematic food.

“Friendly” bacteria in kefir may play a role in blocking the pathway involved in allergic responses, Lisa Richards reports in Chemistry & Industry, SCI’s fortnightly magazine. Research published today [Monday 16 October 2006(DOI 10.1002/jsfa2469)] in the SCI’s Journal of the Science of Food and Agriculture has shown that the milk drink inhibits the allergen specific antibody Immunoglobulin E (IgE). IgE is involved in immune responses to inactivate organisms that might cause disease. However, in the presence of allergens it can also activate cells responsible for the release of histamine, a chemical which stimulates allergic responses, such as inflammation and constriction of airways.

Ji-Ruei Liu’s team of scientists at the National Formosa University, Yunlin, Taiwan, fed mice the milky drink, and found that after 3 weeks, the amount of ovalbumin (OVA) specific IgE was reduced three-fold. Ovalbumin is an allergenic protein found in egg whites, which cause most allergies in young children. Kefir is also reported to prevent food antigens from passing through the intestinal wall.

Liu believes that the milky drink could be a promising tool in the prevention of allergies. “In the future, maybe we can screen out the certain components (bacterial strains or bioactive peptides) from kefir and utilize them in medicine,” he said.

Also in this weeks Chemistry & Industry, UK firm Rigest are looking for backers to develop an air sanitizing system using an enzyme found naturally in human tears. Lactoperoxidase can attack and kill microbes such as ‘flu viruses and the bacteria responsible for MRSA. The system could be used to sanitize the air in airplanes and hospital sick bays.

Overcoming Allergy

Children who were allergic to eggs were able to essentially overcome their allergy by gradually consuming increased quantities of eggs over time, researchers at Duke University Medical Center and the University of Arkansas for Medical Sciences have found in a small pilot study.

“Participants who took a daily dose of egg product over the two-year study period were able to build up their bodies’ resistance to the point where most of them could eat two scrambled eggs without a reaction,” said A. Wesley Burks, M.D., chief of Duke’s Division of Allergy and Immunology and a senior member of the research team. “Egg allergies cause a significant decrease in quality of life for many people, so this study is exciting in that it brings us a step closer to being able to offer a meaningful therapy for these people.”

Egg allergy is one of the most common food allergies among children in the United States, Burks said. Just how many children are allergic to eggs is unclear, but the National Institute of Allergy and Infectious Diseases estimates that 6 percent to 8 percent of children have some type of food allergy. Most children outgrow egg allergy by age 5, but some people remain allergic for a lifetime.

The findings are reported in an advance online edition of the Journal of Allergy and Clinical Immunology and will appear in the journal’s January 2007 print edition.

The study was funded by the National Institutes of Health and the two universities.

The study is the first in a series of studies on food allergy “desensitization” that are under way at Duke and the University of Arkansas. The goal, Burks said, is to offer food allergy sufferers protection from accidental ingestion of items that provoke reactions and, eventually, to induce complete or near-complete tolerance to those items.

Burks and his colleagues modeled the study on a commonly used method for treating seasonal allergy sufferers to alleviate symptoms. In this approach, called immunotherapy, physicians give patients shots containing small amounts of the troublesome allergen in an effort to build their tolerance to it. The therapy works on a cellular level to alter specific immune system cells, called lymphocytes, that play a part in orchestrating allergic reactions and to increase the immune system’s production of antibodies that attack and neutralize allergens, Burks said.

The seven subjects in the study, who ranged from 1 to 7 years of age, had a history of allergic reactions, including hives, wheezing and vomiting, when they consumed eggs or egg products. For safety’s sake, none of the children enrolled had previously experienced a life-threatening allergic reaction, Burks said. As an extra precaution, the subjects received a supply of epinephrine, which is commonly used to treat breathing problems that can occur with food allergy.

Instead of receiving shots, as seasonal allergy sufferers do, the subjects were given small doses of powdered egg orally, mixed in food. “We started the subjects with a very small concentration of egg product — the equivalent of less than one-thousandth of an egg — and then we increased the dose every 30 minutes for eight hours in order to determine the highest dose that each subject could tolerate,” Burks said.

The subjects consumed the first doses in the study clinic. The researchers then gave the children’s parents or caregivers a supply of egg product, allocated into the tolerated doses, which the subjects consumed daily at home, mixed with other foods.

The children returned to the clinic every two weeks. At each visit, the researchers increased the subjects’ dosages until they reached the equivalent of one-tenth of an egg, Burks said. The children then continued to take this “maintenance dose” daily for the duration of the study.

Over time, the children showed both an increase in tolerance to eggs and a decrease in the severity of their allergic reactions, Burks said. At the end of the study period, most of the children could tolerate two scrambled eggs with no adverse reactions.

The researchers now are conducting two follow-up food allergy desensitization studies, Burks said. In one study, subjects receive higher doses of egg to see if this will further reduce their sensitivity or even neutralize the allergy altogether.

The second study focuses on children who are allergic to peanuts, to see if the desensitization approach can build their tolerance and decrease the severity of their reactions. Peanut allergy, which can be life-threatening, affects approximately 1 percent of children under age 5, and its incidence has been on the rise over the past 15 years, according to Burks. Studies have shown that about 20 percent of children with egg or milk allergy will go on to develop a peanut allergy.