C1 protein, showing subunits C1r, C1s, and the C1q tails. Image source: Wikipedia.
New therapies for hereditary angioedema (HAE) (click to enlarge the image).
Acute facial and abdominal attacks were each treated with C1-INH concentrate using a single intravenous dose of 20 U/kg body weight in this study.
663 abdominal attacks were treated in 50 patients and 43 facial attacks in 16 patients.
The time to onset of relief was 20 minutes for abdominal attacks and 28 minutes for facial attacks. The time for complete resolution was 11 hours.
No human immunodeficiency virus, hepatitis virus, or parvovirus B19 infections arose during the study.
The C1-INH concentrate dose of 20 U/kg provides rapid, effective, and safe treatment for successive HAE attacks at abdominal and facial locations.
Prospective study of C1 esterase inhibitor in the treatment of successive acute abdominal and facial hereditary angioedema attacks. Wasserman RL, Levy RJ, Bewtra AK, Hurewitz D, Craig TJ, Kiessling PC, Keinecke HO, Bernstein JA. Ann Allergy Asthma Immunol. 2011 Jan;106(1):62-8. Epub 2010 Nov 20.
Optimal efficacy of C1INH therapy in HAE is achieved at doses ≥50 U/kg, target level ≥0.7 U/ml (70% of normal) http://goo.gl/HJM4X
Comments from Twitter:
@MatthewBowdish (Matthew Bowdish MD): rapid = 20 min