Researchers demonstrate potential mechanism of food allergyJuly 24, 2006Researchers 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. American Gastroenterological Association | |||||||||||||||||||||
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Related Food Allergies Current Events and Food Allergies News Articles Society's lack of food allergies impacts those afflicted with food allergies The level of knowledge and understanding of children with food allergies varies significantly across three key groups: pediatricians and family physicians, the general public and families who have a child with food allergies. The article describing the new findings was published in the September issue of BioMed Central Pediatrics. Students with food allergies often not prepared College students with food allergies aren't avoiding the foods they know they shouldn't eat. Students of all ages are not treated with potentially life-saving epinephrine as often as they should be. And instructors, roommates and friends often are not aware of what to do if a food-allergic student has a reaction. Road pollution blamed for higher allergy risk in kids New evidence blames traffic-related pollution for increasing the risk of allergy and atopic diseases among children by more than fifty percent. What's more, the closer children live to roads, the higher their risk. Licorice extract provides new treatment option for canker sores What common oral condition appears as shallow ulcers of different sizes, affects one in five Americans, can be caused by food allergies and hormonal changes, and also can cause severe mouth pain? National Jewish Medical and Research Center Evaluating Treatment To Prevent Allergic Reactions to Food Researchers at National Jewish Medical and Research Center are conducting trials to evaluate a method to prevent allergic reactions to food. They are feeding peanut- and egg-allergic people increasing doses of an investigational protein extract from the foods to see if they can induce the participants' immune systems to tolerate the food. Treatment for disease that affects estimated 1 in 2000 children gets them to eat again Eosinophilic esophagitis, an inflammatory condition known as EE that often mimics reflux and can cause refusal to eat, affects about 1 in 2000 children in the United States and its prevalence is growing. Researchers from the Indiana University School of Medicine and Riley Hospital for Children report that treatment with oral or swallowed/sprayed steroids results in significant patient improvement, but that if discontinued relapse is common. Research Finds Allergic Children Exposed to Peanuts at Younger and Younger Ages Despite Recommendations To Avoid Until Age 3 The age at which children are exposed to peanuts and have an allergic response has dropped significantly over the last decade, despite recommendations that at-risk families avoid exposing children to peanuts during the first three years of life. NIH selects LIAI for major study on allergy molecular causes and possible treatments A major study that will provide a new window into understanding and potentially treating allergies will be conducted by the La Jolla Institute for Allergy & Immunology (LIAI) under a $5 million federal contract. Scientists puzzled by severe allergic reaction to cancer drug in the middle Southern US A patient's expectations about the side effects of chemotherapy usually focus on nausea, hair loss, fatigue and other side effects. Worries about severe allergic reactions to their therapy is usually not a concern. N.C. A&T food scientist develops process for allergen-free peanuts An agricultural researcher at North Carolina Agricultural and Technical State University has developed a simple process to make allergen-free peanuts. More Food Allergies Current Events and Food Allergies News Articles |
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