Which class of antibody is found on mast cells and basophils?

Which class of antibody is found on mast cells and basophils?

• A. IgG
• B. IgM
• C. IgA
• D. IgE

Answer: (D)

The class of antibody that is found on mast cells and basophils is IgE. This antibody plays a crucial role in the immune response, particularly in allergic reactions and defense against parasitic infections. When antigen binds to IgE on the surface of mast cells and basophils, it triggers these cells to release a variety of chemicals, including histamine, which leads to the symptoms associated with allergy, such as inflammation, itching, and broncho-constriction. This mechanism is essential for helping the body respond to allergens and potential threats.

Other antibody classes, while important in their own right, do not have this specific role in mediating allergic responses or binding to mast cells and basophils. For instance, IgG is the most abundant antibody in serum and is primarily responsible for providing long-term immunity; IgM is usually the first antibody produced in response to an infection; and IgA is found mainly in mucosal areas and secretions such as saliva and tears, making them less relevant to mast cell activation in allergic reactions.