Which complement components activate mast cell degranulation?

Which complement components activate mast cell degranulation?

• A. C3a and C5a activate mast cell degranulation
• B. C4b
• C. C1q
• D. C3b

Answer: (A)

Mast cell degranulation is driven by anaphylatoxins produced during complement activation. The key players that trigger this degranulation are C3a and C5a, which bind to their receptors on mast cells (C3aR and C5aR) and induce release of histamine and other mediators that drive inflammation. C3b and C4b mainly serve as opsonins to tag pathogens for phagocytosis, not to promote degranulation. C1q starts the classical pathway but does not directly cause mast cell degranulation.

Mast cell degranulation is driven by anaphylatoxins produced during complement activation. The key players that trigger this degranulation are C3a and C5a, which bind to their receptors on mast cells (C3aR and C5aR) and induce release of histamine and other mediators that drive inflammation. C3b and C4b mainly serve as opsonins to tag pathogens for phagocytosis, not to promote degranulation. C1q starts the classical pathway but does not directly cause mast cell degranulation.