Lab-on-a-chip detects actual food allergies

Tagged: Food, scanner, Computer Hardware, Technology
Source: Ars Technica - Read the full article
Posted: 3 years 47 weeks ago

According to a recent study that the National Institute of Allergy and Infectious Diseases has published in the Journal of the American Medical Association, nearly one in three Americans believes that they have at least one food allergy. In reality, the same study found, less than one in twenty has a food allergy. This disparity is due, in large part, to the difficult nature of determining if one actually has a food allergy.

Standard allergy tests involve placing a small amount of allergen under a person's skin and monitoring the site for any redness, irritation, or itching. While effective for determining if a reaction has occurred, it does not guarantee that the reaction is an allergic reaction. The other method for testing for food allergies is to have a person simply stop eating the item they believe they are allergic to for a few weeks. If they get better, then it is a sign that the removed food item is an allergen.

A new lab-on-a-chip device built by a chemical engineering team at MIT promises to provide a more accurate measure. Professor Christopher Love's group has developed a lab-on-a-chip that is capable of exposing individual immune cells to selected allergens and examining their response to the potentially allergenic proteins. This new device, which is described in the latest issue of Lab on a Chip, does not simply look for antibody responses from the immune cells as traditional tests do. Love's device screens for small proteins known as cytokines—these are a class of molecule that immune cells produce to call other immune cells to come join in the fight.

This new allergy test would work by drawing a sample of blood from a patient and separating out their white bloods cells. These immune cells would then be exposed to a selected allergen—milk, soy, peanuts, or tree nuts, for example—and then be placed into a massive microarray on the device. The array, produced through a technique known as microengraving, allows researchers to measure the amount of cytokine secreted by each individual cell.

As a proof-of-concept for the device, Love's group is working with researchers at Children's Hospital Boston to pinpoint the relationship between cytokines and allergic reactions. In this study, children who are allergic to milk are, in a controlled environment, being given small amounts of milk to help desensitize them to the allergen. As this test proceeds, Love's device will be used to measure the cytokinic response over the course of the desensitization.