IgE sialylation: unravelling a key anaphylactic mediator.

Immunoglobulin (Ig) E antibodies are heterotetrameric glycoproteins. They are formed by two antigen-binding fragments (Fab) and a fragment crystallizable region (Fc) (1) with seven N-linked glycosylation sites distributed across the heavy chains.(2, 3) Allergen cross-linking of IgE bound to high affinity IgE-receptors (i.e., FceRI) on mast cells (MCs) and basophils induces the release of mediators that cause allergic symptoms.