Alloanti-VIII
inhibitor
Definition:
Antibodies that specifically inhibit
factor VIII and are produced by patient in response to injected factor VIII. (These show normal type I kinetics)
Incidence:
Seen in the following patients:
Hemophilia A – (20 – 25%
of patients)
Detection:
aPTT that is prolonged and not
corrected when mixing studies are performed and if the incubation time is increased to 2 hours at 37oC
it remains prolonged
Therapy:
Corticosteroids to suppress immune
system
Porcine factor VIII
Plasma exchange if severe
