Summary
Factor VIII activity and inhibitor-neutralizing capacity of plasmas of 30 probable
or definite carriers of hemophilia A were compared. The inhibitor-neutralization test
is less useful to recognize the carrier-state than the factor VIII assay. Plasmas
of two carriers belonging to families (in which, in at least one member, the diagnosis
of hemophilia A+ was established) had an inhibitor neutralizing capacity twice as
high as expected from the biological activity, while 28 carriers from hemophilia A- families had an inhibitor neutralizing-capacity equivalent to their factor VIII activity.