A method to profile an individual’s allergic response, using a small blood sample, is reported this week in Nature Communications.

Current approaches to identify the trigger for allergic reactions in an individual often rely on either skin pricks, which can result in very strong immune reactions in some individuals, or require large amounts of blood when the reaction is carried out in a test tube.

Martin Fusseneger and colleagues modified cells to glow in the presence of small amounts of histamines (molecules released during an allergic reaction). Blood samples were exposed to allergens, such as different types of pollen and mite, and then added to the cells. When histamines were present in the blood, indicating an allergic response, the modified cells glowed. In several patients, the method provided similar results to the commonly used skin prick test and required only small amounts of blood.

The modified cells that enabled this method could be further altered to sense other types of molecules, potentially providing a basis for additional diagnostic tests and testing the efficacy of therapeutic drugs.