Factor VIII circulates in noncovalent complex with von Willebrand factor (vWf). The topography of this complex was evaluated by fluorescence energy transfer using factor VIII subunits modified with N-(1-pyrenyl)maleimide (NPM; fluorescence donor) and vWf-derived fragments modified with 7-diethylamino-3-[4'-maleimidylphenyl]-4-methyl coumarin (CPM; fluorescence acceptor). Results from a previous...

Four years' experience with a method for preparing a high-purity, low-fibrinogen, heat-treated factor VIII concentrate is reported. The process, batch adsorption of a cryoprecipitate extract with controlled-pore glass granules, removes 77 percent of the cryoprecipitate fibrinogen, resulting in a final concentrate-specific activity of 0.74 IU factor VIII per mg of protein at a yield of 194 IU fa...

There is now convincing evidence that a high level of coagulation factor VIII is an important risk factor for venous thromboembolism. A factor VIII plasma concentration above 1500 IU/l is associated with an almost 5-fold risk for a first episode of venous thrombosis. In thrombosis patients high factor VIII has been shown to persist over time and is not related to an acute phase reaction. High f...

The interaction of factor VIII with von Willebrand factor (vWF) was investigated on a quantitative and qualitative level. Binding characteristics were determined using a solid phase binding assay and protection of factor VIII by vWF from inactivation by activated protein C (aPC) was studied using three different assays. Deletion mutants of vWF, a 31-kD N-terminal monomeric tryptic fragment of v...

Coagulation factor VIII (FVIII) is a cofactor in the intrinsic pathway of blood coagulation for which deficiency results in the bleeding disorder hemophilia A. FVIII contains a domain structure of A1-A2-B-A3-C1-C2 of which the B domain is dispensable for procoagulant activity in vitro. In this report, we compare the properties of B-domain-deleted FVIII (residues 760 through 1639, designated LA-...

background and objectives: pathogen reduction technologies are among methods to eliminate transfusion transmitted infections. mirasol method using riboflavin in combination with ultraviolet rays is one of them. the aims of this study were to investigate the effectiveness of mirasol method to inactivate some model pathogens as well as examination of the sensitivity of plasma proteins after treat...

Cultured human endothelial cells synthesize and secrete a protein(s) which has Factor VIII antigen but which lacks Factor VIII clot-promoting activity (J. Clin. Invest. 52, 2757-2764, 1973). Von Willebrand factor activity has been identified in medium from cultured human endothelial cells. This activity was demonstrated by the ability to correct the defect in platelet adhesiveness of blood obta...

: A recombinant von Willebrand factor (rVWF) was recently approved in the United States for on-demand treatment and control of bleeding episodes in adults with von Willebrand disease (VWD). In contrast to plasma-derived VWF products available in the United States, rVWF does not contain factor VIII (FVIII). To date, there is no published experience of rVWF in clinical practice. We report the acu...

Human factor VIll-anti-factor VIII comThe extent of dissociation was measured plexes were formed in vitro in slight antiby the recovery of anti-factor VIII activity. gen excess, using plasma of hemophiliacs Increasing resistance of complexes towho were found to have antibodies neuwards dissociation was observed in the tralizing AHF activity. These complexes, plasma of the patients whose titer o...