Complement C1 esterase inhibitor (C1-INH)

Complement C1 esterase inhibitor (C1-INH) is a serine protease inhibitor (serpin) that regulates the activation of the complement and contact systems. It inhibits C1r and C1s in the classical complement pathway, as well as plasma kallikrein, factor XIIa, and factor XIa in the contact system. Deficiency or dysfunction of C1-INH leads to hereditary angioedema (HAE), characterized by recurrent episodes of severe swelling. Recombinant and plasma-derived C1-INH products are used therapeutically to treat and prevent HAE attacks.

Other names

C1 esterase inhibitorC1 inhibitorC1-INH

Irreversible binding and inactivation of target serine proteases (C1s, kallikrein, factor XIIa, XIa) to prevent excessive activation of complement and contact systems.