Hereditary angioedema: a decade of human C1-inhibitor concentrate therapy.

BACKGROUND

C1-inhibitor (C1-INH) is a serine protease inhibitor regulating the complement, kinin-kallikrein, coagulation, and fibrinolytic systems. Hereditary angioedema (HAE) is caused by an inherited deficiency of C1-INH characterized by sudden, recurrent edematous swellings of the subcutaneous or submucosal tissues. The optional therapy for the acute management of HAE is administration of human C1-INH (hC1-INH) concentrate. However, hC1-INH is not available in many countries, in which case fresh frozen plasma is an alternative.

OBJECTIVE

To summarize our experience with hC1-INH concentrate in patients with HAE.

METHODS

Clinical and laboratory information on the effectiveness and safety of hC1-INH administered to relieve 468 acute edematous attacks in 61 patients with HAE was analyzed.

RESULTS

Severe abdominal or subcutaneous attacks and laryngeal edema were consistently relieved by the administration of 500 U hC1-INH concentrate. Symptoms improved within 15 to 60 minutes of administration. Progression of the attacks was never observed, and there were no recurrent attacks within 72 hours. hC1-INH concentrate requirements did not change after repeated use. hC1-INH concentrate proved effective in the management of 94 attacks in 22 children and 6 attacks in 4 pregnant women. Adverse reactions, viral infections, and antibody formation against the purified protein did not occur.

CONCLUSION

The administration of hC1-INH concentrate in HAE is highly effective and safe for the treatment of acute attacks and short-term prophylaxis and in pediatric patients and pregnant women.

CLINICAL IMPLICATIONS

Human C1-INH concentrate is effective and safe for the treatment of acute HAE attacks as well as for short-term prophylaxis.