C1-inhibitor deficiencies (hereditary angioedema): Where are we with therapies?

Hereditary angioedema, an autosomal dominant disorder, presents clinically as recurrent episodes of swelling. It results from either deficient production or function of C1 inhibitor. Acquired angioedema is associated with lymphoproliferative or autoimmune disease. Conventionally attenuated androgens and antifibrinolytics have been used for prophylaxis, both for the long term and presurgically. Fresh frozen plasma and plasma-derived C1 inhibitor concentrate have been used primarily for treatment of acute attacks. All have drawbacks in side effects or potential for infection transmission. New treatments (recombinant C1 inhibitor, icatibant, DX-88, and for acquired angioedema, rituximab) so far show good safety profiles. Early data suggest these may be effective treatment alternatives. The efficacy of current treatment and the potential held by newer agents that target specific elements in complement or kinin pathways are examined. Some agents are likely to have a wider role in treatment of other, more common, forms of angioedema.