George heard from a colleague who is looking for support on a provocative case. A 77-year old woman is experiencing systemic bleeding.
Key laboratory findings:
- von Willebrand factor antigen: 200%
- von Willebrand factor activity by ristocetin cofactor: 100%
- Whole blood lumiaggregometry: no secretion (ATP release) to thrombin, ADP, collagen or arachidonic acid
Could this be acquired von Willebrand disease, type 2?
Acquired storage pool deficiency?
What test would you perform next?