Haemophilia : the official journal of the World Federation of Hemophilia
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Because native circulating factor VIII (FVIII) is maximally stabilized when it is bound to von Willebrand factor (vWf), increased plasma vWf levels may enhance the infused FVIII concentrate intravascular survival and efficacy in severe haemophiliacs. To assess whether the kinetic characteristics and recovery of high purity, plasma-derived (Monoclate-P, Centeon) and recombinant (Bioclate , Centeon) FVIII concentrates are enhanced by increased plasma vWf concentrations, we compared the pharmacokinetic response to a bolus of FVIII infused alone with the response to a bolus infused 2 h after the intranasal delivery of 300 microg of desmopressin acetate (DDAVP) High Concentration Nasal Spray (Stimate, Centeon) in 10 adult severe haemophiliacs. FVIII activity was determined using a one-stage clotting assay on cryopreserved plasma specimens obtained at baseline and at 14 distinct time points (0.25-48 h) following the FVIII infusions. ⋯ The mean differences in recovery, area under the curve (AUC), half-life, and clearance (Cl) were not significantly altered. Subgroup analysis revealed statistically significant increases in Vss and MRT (P = 0.025 and P = 0.012, respectively) following the administration of intranasal DDAVP in the Monoclate-P cohort, but not in the Bioclate group. These data suggest that even modest pharmacologically induced increases in plasma vWf can favourably affect the kinetics of high-purity, plasma-derived FVIII concentrates in severe haemophiliacs.