Treatment with C1-esterase inhibitor concentrate in type I or II hereditary angioedema: a systematic literature review.

Hereditary angioedema (HAE) due to C1 esterase inhibitor (HAE-C1-INH) deficiency is a rare genetic disorder presenting with recurrent episodes of skin swellings, abdominal pain attacks, and potentially fatal laryngeal edema. This study was designed to review the efficacy and safety of pasteurized, human, plasma-derived C1-INH concentrate for the treatment of patients with HAE-C1-INH. A systematic search of electronic databases up to December 2011 was performed without language or date restrictions. Two reviewers completed the study selection using predefined inclusion criteria, tabulated, and analyzed the data. The data were inappropriate for meta-analysis; thus, a qualitative synthesis was performed. We identified 89 studies (≍2000 patients) that investigated C1-INH. Replacement therapy with C1-INH significantly shortened time to onset of symptom relief in HAE attacks compared with placebo in a randomized controlled trial, and similar improvements were consistently reported in observational and descriptive studies, accompanied by improvements in patients' quality of life. C1-INH has been shown to be effective for patients receiving home therapy and short- and long-term prophylaxis. Treatment with C1-INH was generally well tolerated. Administration of C1-INH was not associated with transmission of viruses or development of autoantibodies irrespective of treatment duration. This research provides additional confirmation of the efficacy of C1-INH in the treatment and prevention of HAE attacks. C1-INH is generally safe and well tolerated and has an excellent safety record for over 25 years of clinical use.