Management of bleeding disorders: basic science

Development of factor VIII (FVIII) inhibitors is the most severe and challenging complication of haemophilia A treatment and represents the highest economic burden for a chronic disease. Therefore, major research efforts are ongoing to optimize the therapeutic approaches able to minimize this complication. FVIII inhibitors have variable immuno-reactivity against different FVIII concentrates and generally have a lower reactivity against von Willebrand factor (VWF)-containing FVIII concentrates than plasma-derived FVIII (pdFVIII) or recombinant FVIII (rFVIII) that are devoid of VWF, in particular when the inhibitors are directed against the light chain of FVIII. This paper provides an overview of several in vitro and in vivo studies that compared three clinically available clinical FVIII products (Kogenate®, Bayer AG, Leverkusen, Germany; Advate®, Baxter Healthcare, Zurich, Switzerland; and Fanhdi®, Grifols S.A., Barcelona, Spain) in order to evaluate the functional actvity of the FVIII fractions in rFVIII that cannot bind VWF; explore the use of the thrombin generation assay (TGA) as a potential tool for optimizing the choice of FVIII concentrate for use in haemophilia A patients with inhibitors; compare the kinetics of the interactions between anti-FVIII antibodies and FVIII both in the presence/absence of VWF, using surface plasmon resonance.