Immunity
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Comparative Study
Basophils play a pivotal role in immunoglobulin-G-mediated but not immunoglobulin-E-mediated systemic anaphylaxis.
Anaphylaxis is an acute, severe, and potentially fatal systemic allergic reaction. Immunoglobulin E (IgE), mast cells, and histamine have long been associated with anaphylaxis, but an alternative pathway mediated by IgG has been suggested to be more important in the elicitation of anaphylaxis. ⋯ Upon capture of IgG-allergen complexes, basophils released platelet-activating factor (PAF), leading to increased vascular permeability. These results highlight a pivotal role for basophils in vivo and contrast two major, distinct pathways leading to allergen-induced systemic anaphylaxis: one mediated by basophils, IgG, and PAF and the other "classical" pathway mediated by mast cells, IgE, and histamine.