C1 Inhibitor ( C1- INH ) Deficiency

C1 inhibitor (C1-INH) is a crucial protein that regulates the complement and contact activation systems of the immune response. It functions by inhibiting the C1 complex in the complement system and controlling the activation of factors in the contact system, including kallikrein and factor XIIa. This regulation helps prevent excessive inflammation and inappropriate activation of immune responses, which could otherwise lead to tissue damage.

The C1 inhibitor test measures both the quantity and functional activity of this protein in the blood. Abnormal levels or dysfunction of C1-INH can result in conditions such as hereditary angioedema (HAE) or acquired angioedema, characterized by recurrent episodes of severe swelling in various body parts. Accurate measurement of C1-INH levels is essential for diagnosing these conditions, assessing disease severity, and monitoring treatment effectiveness. Understanding C1-INH status aids in proper management and helps guide therapeutic strategies for patients with angioedema.