Influence of Factor VII on the Assay of Factor VIII by the One Stage Method Using Wettable Surface

Summary

The influence of factor VII activated by Contact Product (i. e. the product of the reaction between factor XII and XI) on the factor VIII determination by the partial thromboplastin time with kaolin is described. There is an important decrease in clotting time when, with a constant amount of factor VIII, the concentration of factor VII is increased. This difference is unimportant from a practical point of view; but this does not distract from the possibility that the minute amount of thrombin generated by the XII-VII pathway may be of great practical interest, because it may be capable of activation factors V and VIII as well as influencing platelet metabolism and thus induce hemostasis, especially when the intrinsic pathway is blocked.

• References

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