New test for food allergies
26 Jul 2010 by Evoluted New Media
An allergic reaction to milk, peanuts, eggs and soy can be life-threatening, but current allergy tests can be unreliable so a chemical engineer from MIT has developed a test to screen individual immune cells for allergic responses.
An allergic reaction to milk, peanuts, eggs and soy can be life-threatening, but current allergy tests can be unreliable so a chemical engineer from MIT has developed a test to screen individual immune cells for allergic responses.
The test involves screening for cytokines – small proteins produced by T cells when an allergic response is initiated. Blood must be drawn from the patient, and white blood cells – including T cells – are isolated from the sample. The cells are exposed to potential allergens and placed into 100,000 individual wells arranged in a lattice on a soft rubber surface.
Using a technique called microengraving, researchers make prints of the cytokines produced by each cell on the surface of a glass slide. The amount of cytokine produced by each individual cell can be measured precisely. The cytokines of most interest are IL4 IL5 and IL9.
Christopher Love – who developed the test – hopes it could allow doctors to diagnose food allergies with a simple blood test which is faster and more reliable than current tests.
“With a large number of diagnoses, it ambiguous,” he says, “A lot of times it’s almost circumstantial whether you’re allergic to one thing or another.”
Current testing involves placing potential allergens under the skin of a patient’s arm; if they have antibodies specific to that allergen, immune cells in that area will release histamines causing itching and redness. However, these tests can be unreliable – the patient may not be allergic to the particular allergen even if there is an immune response.
Food allergies occur when the body’s immune system mistakes a protein in food for something harmful and triggers immune responses – such as rashes, hives, difficulty breathing or gastrointestinal distress. Some allergies can provoke life-threatening anaphylactic shock.
Love is now working with Dale Umetsu, professor of paediatric immunology at Children’s Hospital Boston on a project to pinpoint the relationship between cytokine activity and allergic reactions by tracking the response of cells of children with milk allergies as they undergo desensitising treatment.
