Aspects of C1-inhibitor biochemistry and pathophysiology.

During the last few years, the structure and function of human C1-inhibitor have been elucidated. Chromogenic substrate assays for determination of C1-inhibitor activity in plasma are available, and have proved to be of value not only for the diagnosis of hereditary angioedema but also in acquired diseases involving C1-inhibitor, such as cold urticaria and autoimmune disorders as well as acute-phase types of disease states.