Measurement of serum levels of which immunoglobulin can serve as a screening test for allergies?

The measurement of serum levels of immunoglobulin E (IgE) is specifically utilized as a screening test for allergies. IgE is associated with the body's allergic responses and is produced in increased amounts during hypersensitivity reactions to allergens, such as pollen, dust mites, and certain foods. When the immune system encounters an allergen, it triggers a response that leads to the production of IgE antibodies, which then bind to tissues and mast cells, resulting in the release of histamine and other chemicals that cause allergy symptoms.

For individuals with allergic conditions, elevated serum IgE levels can indicate sensitivity to specific allergens, making it a crucial marker in allergy testing. In contrast, IgM, IgD, and IgG serve different roles in the immune response; IgM is primarily involved in the early stages of infection, IgD is thought to function mainly as a receptor on B cells, and IgG is the most abundant antibody in serum that provides long-term immunity and is involved in secondary immune responses. Hence, they are not used as screening tests for allergies like IgE is.