ASCP ASCP-MLT Question Answer
Allergen-specific IgE, synthesized in response to allergens, becomes fixed to receptors on cellular membranes, especially those of basophils. If these receptor-bound IgE molecules are aggregated on re-exposure to specific allergen, both mast cells and basophils produce mediators that result in the allergic response. IgE-antigen interaction at the cell surface causes degranulation of cells and release of substances including: histamine, SRS-A, platelet activator, a kallikrein, and an eosinophil chemotactic factor. Basophils are the principal cells that bind IgE antibody while their number of receptor sites is proportional to serum IgE levels. Eosinophils are drawn to the site by the basophil chemotaxis mechanism, but are not the main cell which binds the IgE antibody.
Immunology
The mediator cells that bind MOST to IgE antibodies are: