Total hemolytic activity of serum (CH50), complement components C3 and C4, alpha 1antitrypsin (alpha 1AT), alpha 1antichymotrypsin (alpha 1X), antithrombin III (AT III), alpha 2 macroglobulin (alpha 2M), and inter-alpha-inhibitor (I-alpha-I) were measured in 23 Japanese and 19 European children with