Non-clinical sciences/Immunology · Immunoglobulins

IgE

What it means

Lowest serum concentration. Binds high-affinity FcεRI on mast cells & basophils; antigen cross-linking triggers degranulation (histamine, tryptase, leukotrienes) → type I hypersensitivity. Raised in atopy (asthma, eczema, allergic rhinitis) and parasitic (helminth) infection.

Worked example

Anaphylaxis, allergic rhinitis and acute urticaria are IgE-mediated; tryptase rises after mast-cell degranulation and can confirm anaphylaxis retrospectively.

In the exam

An antibody present at the lowest serum level coats mast cells; when cross-linked by allergen it triggers immediate degranulation and wheeze within minutes.

What settles it

IgE drives immediate (type I) allergy and anti-parasite responses; the late/most-abundant antibody is IgG.

Classically confused with

IgG

Source: StatPearls — Immunoglobulin