Acquired C1 esterase inhibitor deficiency is a rare condition associated with autoimmune or low-grade lymphoproliferative disorders. Adults or elderly patients are most commonly affected. The diagnosis is suspected when patients present with recurrent angioedema and low serum levels of C4 with normal levels of C3. Low levels of C1q and low C1 esterase inhibitor activity confirm the diagnosis. I...

Several lines of experimental evidence have suggested that one or more peptides that can enhance vascular permeability may be released from the second component ofhuman complement, C2 (1-5) . This possibility is important to understanding the molecular mechanisms that lead to bouts of circumscribed edema to which persons with hereditary angioneurotic edema (HANE)' are susceptible. Persons with ...

Hereditary angioedema (HAE) is a potentially life-threatening disease caused by mutations in the gene encoding the serine protease inhibitor (serpin) C1 inhibitor (C1-inh). The mutations cause decreased functional plasma levels of C1-inh, which triggers unpredictable recurrent edema attacks. Subjects suffering from HAE have been classified in type I patients with decreased functional and antige...

Human C1-esterase inhibitor (C1-INH) is a unique anti-inflammatory multifunctional plasma protein best known for its key role in regulation of the classical complement pathway, contact activation system and intrinsic pathway of coagulation. By sequence homology and mechanism of protease inhibition it belongs to the serine proteinase inhibitor (serpin) superfamily. However, in addition to its in...

OBJECTIVE To minimize complement-mediated damage in acute relapses of neuromyelitis optica (NMO) by adding treatment with a complement inhibitor, purified C1-esterase inhibitor, to the current standard of care (high-dose glucocorticoids). METHOD We conducted an open-label phase 1b safety and proof-of-concept trial in 10 patients with NMO-immunoglobulin G seropositive NMO or NMO spectrum disea...

Using components purified from human plasma, we have examined the effects of C1 inhibitor (C1 INH), the primary inhibitor of activated Hageman Factor (HFa) and Hageman factor fragment (HFf), on Hageman Factor (HF) autoactivation. When Hageman factor was exposed to a negatively charged surface, provided by either a glass cuvette or dextran sulfate, the addition of C1 INH gave a dose-dependent in...

BACKGROUND Immune-mediated hemolytic anemia (IMHA) is the most common hematologic immune-mediated disease in dogs. Complement fixation on erythrocytes causes hemolysis. Complement inhibition decreases hemolysis in people with the hemolytic disease and also may prove effective in treating IMHA in dogs. HYPOTHESIS/OBJECTIVES Evaluate the in vitro efficacy of 2 complement inhibitors used in huma...

BACKGROUND : Agents for prophylaxis of hereditary angioedema (HAE) have been available in the United States for several decades, but their usefulness is limited by side effects and they cannot be used at all in some patients. No agents have been available in the United States to specifically treat acute attacks. HAE types I and II are associated with low functional levels of C1 inhibitor, and e...