Summary
The development of inhibitors that neutralise the function of factor VIII (FVIII)
is currently not only the most challenging complication associated with the treatment
of haemophilia A but it also increases the disease-related morbidity as bleeding episodes
do not respond to standard therapy. The main short-term goal of the treatment of inhibitor
patients is to control bleeding episodes while the long-term one is to permanently
eradicate the inhibitor by immune tolerance induction, particularly in the case of
high-titer antibodies. Due to some in vitro studies and clinical observations, some
investigators have suggested that FVIII concentrates containing von Willebrand factor
(VWF) may be less immunogenic than high-purity or recombinant FVIII products. It has
also been suggested that success rates for immune tolerance induction are higher when
plasma-derived FVIII products are used. The currently available data from laboratory
and clinical studies on the role of VWF in inhibitor development and eradication in
haemophilia A is critically analysed in this review. As a result, we have not found
definitive evidence supporting a role for product type on inhibitor incidence and
inhibitor eradication in haemophilia A patients.
Keywords
FVIII - inhibitors - haemophilia A - immune tolerance induction (ITI) - VWF