The Complement C1 Esterase Inhibitor Functional Blood Test, also known simply as the C1 Inhibitor Blood Test, is commonly ordered to diagnose hereditary angioedema (HAE), a condition in which severe and recurrent episodes of swelling affect the face, airway, intestinal tract and/or limbs. C1 esterase inhibitor controls C1, the first component of the complement system, a part of the body’s innate immune system. The C1 Inhibitor Blood Test is an enzyme immunoassay (EIA) that evaluates the function of C1 esterase inhibitor. Test results are reported as a percentage of mean normal activity:
Abnormal: <41%
Equivocal: 41% to 67%
Normal: >67%
The C1 Inhibitor Blood Test is also known as C1 Esterase Inhibitor, C1 Inactivator, Esterase Inhibitor, and Hereditary Angioedema Test. Fasting is not required prior to this test, and results will be available within two to three days. Insurance and a doctor’s order are not required to purchase this test.
For more information about the complement system, see details on the CH50 Blood Test page. Walk-In Lab also offers a C1q Blood Test, C2 Blood Test and C4 Blood Test.
