SERPING1 and hereditary angioedema: In a double-blind, placebo-controlled cross-over study (22 patients in two 12-week periods), the nanofiltered C1-INH concentrate Cinryze (ViroPharma Inc., USA), in a dose of 2-times 1,000 U/week, reduced the number of HAE attacks from 12.7 to 6.3 [59].