The development of an immune response to infused factor VIII is a complication affecting many patients with hemophilia A. Inhibitor antibodies bind to antigenic determinants on the factor VIII molecule and block its procoagulant activity. A patient-derived inhibitory immunoglobulin G4kappa antibody (BO2C11) produced by an immortalized memory B-lymphocyte cell line interferes with the binding of...

The development of an immune response to infused factor VIII is a complication affecting many patients with hemophilia A. Inhibitor antibodies bind to antigenic determinants on the factor VIII molecule and block its procoagulant activity. A patient-derived inhibitory immunoglobulin G4k antibody (BO2C11) produced by an immortalized memory B-lymphocyte cell line interferes with the binding of fac...

Protein-C inhibitor (PCI) is a newly described plasma inhibitor directed against a vitamin-K-dependent serine protease, activated protein-C, which is involved in the inactivation of factor V and factor VIII. Marlar and Griffin have reported that PCI activity is absent in the plasma of patients with congenital combined factor V/VIII deficiency. We have measured the levels of PCI in the plasma of...

Factor VIII auto- and alloantibodies neutralise porcine factor VIII to a lesser extent than factor VIII of human origin. The reduced reactivity of the porcine molecule, predominantly due to sequence variation in the A2 and C2 domains, has been the rationale for using porcine factor VIII to secure haemostasis for patients with factor VIII inhibitors. Porcine factor VIII has been shown to provide...

To study the interrelationships of the major human coagulation pathways, factor X activation in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin were added to plasma samples containing 3H-labeled factor X, and the time course of factor X activation was determined. At a 1/250 dilutio...

The course and treatment of a life-threatening hemorrhagic episode in a patient with hemophilia A whose plasma contained a high concentration of an inhibitor of factor VIII activity is presented. The inhibitor of factor VIII was localized to the most anodal fractions of immunoglobulin G on electrophoresis, and was thus presumed to be an antibody directed against factor VIII. No therapeutic bene...

The plasma clearance rates of factors IX and VIII were determined in patients with hemophilia A and B who had received factor replacement by prolonged, continuous infusion of factor concentrates. The clearance rates were calculated by dividing the factor infusion rates by the steady-state plasma factor activities corrected for base-line factor activities. The mean factor IX clearance rate in ei...

DGOOC 2003. 17. Rosendaal G, van den Berg HM, Lafeber FPJG et al. Pathologie der Synovitis und hämophilien Arthropathie. Orthopäde 1999; 28: 323–328. 18. Scharrer I, Bray GL, Neutzling O. Incidence of inhibitorsin hemophilia A patients – a review of recent studies of recombinant and plasma-derived factor VIII concentrates. Haemophilia 1999; 5:

A circulating anticoagulant against factor VIII activity was demonstrated in the plasma of a boy from a family with both factor VIII deficiency and prolonged bleeding time. However, the factor VIII-related antigen, ristocetin-induced platelet aggregation activity, platelet retention in glass bead columns, platelet aggregation with adenosine 5'-diphosphate, collagen and epinephrine, and clot ret...