The product is composed of purified endogenous complement component-1 esterase inhibitor (hC1INH) isolated from human plasma. The primary function of endogenous C1INH is to regulate the activation of the complement and contact system pathways. It does this through inhibition of several target proteases within these pathways including activated C1s, kallikrein, factor XIIa and factor XIa. C1 esterase inhibitor has also been shown to inhibit the action of thrombin within the coagulation pathway, and tPA and plasmin within the fibrinolytic pathway. Deficiency of C1-inhibitor permits plasma kallikrein activation, which leads to the production of the vasoactive peptide bradykinin. Additionally, C4 and C2 cleavage goes unchecked, resulting in auto-activation of the complement system. Down-stream effects of the lack of enzyme inhibition by C1 esterase inhibitor results in swelling due to leakage of fluid from blood vessels into connective tissue and consequently the presentation of hereditary angioedema (HAE). Human C1-esterase inhibitor https://www.creativebiomart.net/therapeutic-proteins/p/16/endogenous-complement-component-1-esterase-inhibitor-hc1inh/