Which immunoglobulin class is associated with allergic reactions?

The immunoglobulin class that is associated with allergic reactions is IgE. This particular antibody plays a crucial role in the immune response to allergens. When an individual is exposed to an allergen, IgE binds to the specific allergen and triggers the release of various substances, including histamine, from mast cells and basophils. This release is what causes the symptoms associated with allergic reactions, such as itching, swelling, and mucus production.

IgE is typically present in very low concentrations in the serum, but its role is significant in mediating hypersensitivity reactions, including asthma, hay fever, and anaphylaxis. The presence of elevated IgE levels in a patient often indicates an allergic condition or a parasitic infection, making it a key component in diagnosing and understanding allergic responses.

Other immunoglobulin classes serve different functions in the immune system. IgA primarily protects mucosal surfaces, IgM is involved in the initial immune response and is the first antibody produced upon exposure to an antigen, and IgG provides long-term immunity and is the most abundant immunoglobulin in the blood. Each of these classes has unique properties and roles, but IgE is specifically linked to allergic reactions and responses to environmental allergens.