Basophils are types of cells in the immune system called leukocytes. They are typically the least abundant variety of these cells, but during basophil activation, they can travel quickly to injured sites where there is inflammation. During this process, different proteins such as cytokines, and others that regulate inflammatory responses and allergic reactions, are released by basophils. Medical tests can detect these cells by identifying markers used to find protein antigens on their surface. These include Cluster of Differentiation (CD) proteins such as CD203c, which are typically attached to molecules on the surface of cells.
Studies have found other protein markers during allergic reactions in which basophil activation takes place. These substances are often identified through blood tests and laboratory procedures such as flow cytometry, which can be used to analyze each cell and surface proteins. Such a procedure can also be used to develop pharmaceutical drugs and screen the ones that are the most effective. Many medical tests function by activating the cells in the laboratory to monitor allergic reactions to different compounds.
During an allergic reaction, basophils and other immune components called mast cells release an inflammation-inducing compound called histamine. Basophil activation, therefore, is often thought to trigger physical reactions in people with allergy related illnesses. The process sometimes leads to shock and airway obstruction if it is not regulated by medication.
Basophil activation occurs when an antibody called immunoglobulin E (IgE) is exposed to a receptor on the immune cell. Granules are structures typically inside a basophil that contain substances that can start an allergic reaction. The binding usually activates the cell and the substances are released when it undergoes degranulation, during which the inner surface of the granules typically merge with the outside of the basophil membrane.
A marker called CD63 is often present within the granules, so allergy tests performed by analyzing blood or skin responses usually check for the molecule. Various substances are mixed with a specific allergen in a test tube, which are then heated, to analyze a blood sample. These include a type of interleukin, which is typically responsible for the communication between cells during an immune response.
While basophils are not as prevalent as other immune cells, if one is sensitized to IgE, they will be more prevalent than other antigen-specific cells in the blood. Basophil activation and other compounds present during this reaction are often measured to diagnose food allergies. Physicians often perform these tests to find treatments for conditions as well.
