Combined factor V and factor VIII deficiency (F5F8D) is a rare, autosomal recessive congenital bleeding disorder with a prevalence of 1:1,000,000. Individuals present with a variable clinical bleeding phenotype, elevated prothrombin time (PT) and partial thromboplastin time (PTT), and plasma levels of factor V and VIII of 5–30%. Mutations in 2 proteins, LMAN1 and MCFD, required for concurrent t...

Hematol Transfus Int J 2017, 4(2): 00078 those using the anti-coagulant agent, warfarin [4,5]. One case of a patient undergoing coronary artery bypass grafting was noted among 7cases of surgery-associated acquired hemophilia [2]. A 66-year-old man underwent aortic valve replacement for severe aortic valve stenosis. After surgery, he was administered warfarin (2mg/day) for anticoagulation and th...

we prepared a highly purified and relatively heat stable form of factor viii which contained 25 units per ml (u/ml) activity using peg-4000 and developed an effective and new manufacturing process. heat treatment was performed at 80°c for 72 hrs in the presence of different stabilizers. in our studies, we used different organic solvents as preservatives to maintain factor viii activity, since f...

Von Willebrand factor (VWF) has been proposed to reduce the immunogenicity of therapeutic factor VIII (FVIII) in patients with hemophilia A. Using FVIII-deficient mice, we compared the immunogenicity of different preparations of plasma-derived (pd) and recombinant (r) FVIII. Treatment of mice with pdFVIII induced significantly lower titers of FVIII inhibitors, as measured by ELISA and in vitro ...

Factor VIII procoagulant (VIII:C) activity, factor VIII coagulant antigen (VIII:CAg), von Willebrand ristocetin cofactor (VIIIR:RC) activity, factor VIII-related antigen (VIIIR:Ag), and plasma fibronectin (CIg; cold-insoluble globulin) were measured in the heparin precipitable fraction (HPF) and heparin supernatant fraction (HS) of normal human plasma. Following heparin induced precipitation, m...

Around one third of boys with severe hemophilia A develop inhibitors (neutralizing antibodies) against their therapeutic factor VIII product. This adverse effect may result in more life-threatening bleeding, disability, impaired quality of life, and costly care. We compared the incidence of inhibitors in boys treated with the three factor VIII products most used in France: one plasma-derived (F...

To understand why this quest was so prolonged, one needs to go back to the technologies of the 1970s and 1980s. Factor VIII is a cofactor for conversion of factorX to factorXa by activated factor IX and is the rarest of all the clotting factors in blood. Not surprisingly, it was the last but one of the classical blood coagulation factors to yield to the advance of molecular biology (in 1984, 2 ...

Generation of coagulation factor Xa by the intrinsic pathway protease complex is essential for normal activation of the coagulation cascade in vivo. Monocytes and platelets provide membrane sites for assembly of components of this protease complex, factors IXa and VIII. Under biologically relevant conditions, expression of functional activity by this complex is associated with activation of fac...

Factor IXa was shown to inactivate both factor VIII and factor VIIIa in a phospholipid-dependent reaction that could be blocked by an antifactor IX antibody. Factor IXa-catalyzed inactivation correlated with proteolytic cleavages within the A1 subunit of factor VIIIa and within the heavy chain (contiguous A1-A2-B domains) of factor VIII. Furthermore, a relatively slow conversion of factor VIII ...