Micro & Immunology · single question
Anaphylaxis is mediated by which immunoglobulin?
Show answer and explanation
Correct answer: A. IgE
- A. Correct. Anaphylaxis is a Type I (immediate) hypersensitivity reaction mediated by IgE. On sensitization, IgE binds to mast cells/basophils. On re-exposure, allergen cross-links IgE → massive histamine + mediator release → anaphylaxis.
- B. Incorrect. IgM is the first antibody in primary immune response and activates complement — not IgE-mediated anaphylaxis.
- C. Incorrect. IgG mediates secondary immune responses, complement activation, and opsonization — not immediate hypersensitivity.
- D. Incorrect. IgA is found in secretions (saliva, tears) for mucosal immunity — not anaphylaxis.
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