Doctors can also perform blood tests that directly measure the presence of particular antibodies in the patients' blood. However, one drawback to both of these tests is that the presence of antibodies to a particular allergen does not necessarily mean that the patient is allergic to that substance, leading to false positive results.
Love's new technology, developed with funding from the Deshpande Center for Technological Innovation, the Dana Foundation and the NIAID, takes a different approach. Instead of detecting antibodies, his system screens the patient's immune cells for small proteins known as cytokines. Immune cells such as T cells produce cytokines when an allergic response is initiated, attracting other cells to join in the response.
To perform the test, blood must be drawn from the patient, and white blood cells (which include T cells) are isolated from the sample.
The cells are exposed to a potential allergen and then placed into about 100,000 individual wells arranged in a lattice pattern on a soft rubber surface. Using a technique known as microengraving, the researchers make "prints" of the cytokines produced by each cell onto the surface of a glass slide. The amount of cytokine secreted by each individual cell can be precisely measured. For food-allergy testing, the cytokines of most interest are IL4, IL5 and IL9.
The "gold standard" for diagnosing a food allergy is to see what happens when the patient is given the food in question (in a controlled setting, to ensure safety), but that is not often done outside of allergy research clinics, says Assa'ad.
Love is now working with Dale Umetsu, professor of pediatric immunology at Children's Hospital Boston, on a project they hope will pinpoint the relationship between cytokine activity and allergic reactions. In that study, children with milk allergies ar
|Contact: Jennifer Hirsch|
Massachusetts Institute of Technology