Summary
This study examined the hypothesis that non-inhibitor haemophilic plasma contains
antibodies which are specific for sites other than the active procoagulant site on
factor VIII, and that some of them might be sufficiently close to the active site
that pre-incubation of such plasma with factor VIII would block the subsequent binding
of inhibitor antibody. Among the 26 non-inhibitor plasmas examined, none was found
to contain such blocking antibody. This result does not eliminate the possibility
that antibody is present in such non-inhibitor plasmas which is neither specific for
the active enzyme site of factor VIII nor capable of blocking the binding of antibody
which does have that specificity.
