Factor IX concentrates were evaluated for their factor VII content and for the presence of activated factor VII through use of a coupled amidolytic assay insensitive to activated factor VII and a clotting assay sensitive to activated factor VII. The factor VII content of the concentrates studied (except for one concentrate purposely produced to exclude factor VII) varied between 33 and 621 U/vi...

Residual activated coagulation factor XI (FXIa) has been suggested to play an important role in thromboembolic events associated with the use of intravenous immunoglobulin (IVIG) lots. This study investigated the predominant plasma proteases in 42 IVIG lots from 4 Chinese manufacturers. In one-stage clotting assays, the procoagulant activities of factors II, VII, IX, X, XI, and XII were quantif...

Factor IXCH is cleaved upon incubation with human Factor XIa and calcium; however, cleavage of this protein is not observed by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis under nonreducing conditions. Under reducing conditions, the rate of disappearance of the zymogen parallels both the appearance of the heavy chain and the generation of clotting activity. In addition, a pro...

Clotting factor concentrates (CFCs) underwent tremendous modifications during the last forty years. Plasma-derived concentrates made the replacement therapy feasible not only in the hospital but also at patients' home by on-demand or prophylactic regimen. Virucidal methods, implemented soon after hepatitis and AIDS outbreak, and purification by Mabs made the plasma-derived concentrates safer an...

The precise quantitation of activated factors in human factor IX concentrates has been accomplished with the use of recently developed, specific assays for factors IXa, Xa, and thrombin. The assay for factor IXa, which measures the initial rate of 3H-factor-X activation, was shown to be specific for factor IXa in the concentrates. Activated factor IX concentrates contained 1.0-2.3 microgram/ml ...

background: factor viii administration to hemophilia a patients results in an immune response (inhibitor formation) which significantly complicates the therapy. the present study was performed to determine the prevalence of inhibitor development in hemophilia a patients receiving recombinant factor viii therapy. materials and methods: this was an observational descriptive study. clotting factor...

Increased plasma levels of fibrinogen, factor VIII (FVIII), factor IX (FIX), factor XI (FXI) and prothrombin all were reported to be independent risk factors of venous thromboembolism (VTE). However there is only limited information on the molecular basis of these plasma phenotypes. In addition some of these plasma phenotypes may form clusters, which may point to defects in common pathways affe...