Clinical significanceClinical indicationsSample typePreparation
Clinical significance
C1 inhibitor belongs to the serpin family and inhibits the serine proteases of the complement and coagulation systems. An inherited deficiency of C1 inhibitor causes angioedema. An acquired deficiency is found in lymphoproliferative and connective tissue diseases and in autoimmune diseases.
Clinical indications
C1 inhibitor testing can be used to detect acquired deficiencies and monitor their course, and to investigate congenital deficiencies.
Sample type
The patient must have a blood sample taken.
Preparation
You must fast for at least 8 hours; a small amount of water is allowed.