A Patient Is Admitted with Prolonged Epistaxis and Prolonged Bleeding

Multiple Choice

A patient is admitted with prolonged epistaxis and prolonged bleeding from a recent tooth extraction. Initial screening workup reports prolonged APTT and BT, and abnormal aggregation on the PFA. Which of the following tests would not help define the disorder?

A) von Willebrand's factor activity
B) von Willebrand's factor antigen
C) Factor VIII assay
D) Prothrombin time