Use

This test is useful for diagnosing hereditary angioedema and for monitoring the levels of C1 esterase inhibitor in response to therapy. C1 esterase inhibitor deficiency leads to inappropriate activation of C1, causing the release of kinin-like peptides that increase vascular permeability, resulting in acute edema. The condition is inherited in an autosomal dominant manner and responds to therapy with attenuated androgens. Despite normal antigen levels, some cases require functional measurements due to presence of nonfunctional proteins.