1. Definition:
IgE is primarily involved in allergic reactions and responses to parasitic infections.
2. Characteristics and function:
- Appearance: IgE is a monomeric antibody similar in structure to IgG but with a different constant region.
- Function: It binds to allergens and triggers the release of histamine and other inflammatory mediators from mast cells and basophils, resulting in allergic symptoms.
- Role in allergy: Elevated levels of IgE are associated with allergic diseases such as asthma, hay fever, and anaphylaxis.
- Parasitic Defense: IgE also plays a role in protecting the body from parasitic infections, particularly helminths (worms).
- Minimal serum levels: IgE is present in very low concentrations in serum compared to other antibody classes, reflecting its specialized role.