Hageman (contact) factor
Last reviewed 01/2018
Factor XII, Hageman factor, is a plasma protein at the centre of a number of plasma protease cascades involved in inflammation. It is part of the beta-globulin fraction of plasma proteins.
It is activated by:
- exposed collagen
- basement membrane
- endotoxin
- negatively-charged surfaces
- glass
- endogenous substances e.g. kallikrein
It stimulates:
- directly, the intrinsic pathway of blood coagulation
- indirectly, the extrinsic pathway of blood coagulation
- the kallikrein-kinin system
- the plasmin fibrinolysis system
- indirectly via kallikrein and plasmin, the complement cascade