The Immunoglobulin E test measures immunoglobulin E (IgE) in your blood. IgE is an antibody produced by your immune system in response to allergens.

Immunoglobulin E (IgE) is a unique antibody isotype found exclusively in mammals, playing critical roles in immune response and allergic reactions.

Key Characteristics Molecular Structure: • Consists of two heavy (ε chain) and two light chains • Four Ig-like constant domains (Cε1–Cε4) • Predominantly found in tissues, attached to mast cells and basophils

Primary Biological Functions Immune Defense: • Protects against parasitic infections • Defends against venoms • Triggers immediate hypersensitivity reactions • Activates mast cells and basophils through Fc epsilon RI receptor

Clinical Significance Diagnostic Implications: • Associated with allergic conditions • Linked to autoimmune disorders

Plays role in: • Anaphylactic reactions • Drug allergies • Bee sting reactions • Atopic march (progression of allergic diseases)

Potential Autoimmune Connections: • Detected in multiple autoimmune conditions • Can indicate disease activity in systemic lupus erythematosus • Contributes to inflammatory immune responses

IgE represents a complex and critical component of the mammalian immune system, with far-reaching implications for health and disease.