May 4 2019
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?
Comments (3)
Bleeding Disorders
Have to agree with Bob and Dr
Have to agree with Bob and Dr. Favaloro on need for information. Was a FVIII:C performed? what are the screening coagulation tests? Did they run ristocetin platelet aggregations (RIPA)? I would also like to see if her meds and supplements could have been interfering with the PLT aggs. Particularly was she taking something like a glucosamine supplement?
Agree with Bob, that there is
Agree with Bob, that there is a paucity of information. I guess you can’t yet discount a type 2 AVWD as yet (ratio of RCo/Ag is ~0.5, so maybe some absorption of HMW VWF occurring somewhere), but doesn’t explain the PLT agg data. If you had VWF:collagen binding available, or VWF multimers, then you could get confirmation of a reduced HMW VWF. Alternatively, the VWF:Ag could be falsely high if the test was performed by LIA and the patient has high RF or human anti-mouse antibody (HAMA). The most striking results so far are the lack of ATP release. But have anti-plt meds been ruled out? At the moment, we don’t even have basic coags; for example, could be an acquired inhibitor, and the PLT agg data could just be anti-PLT meds. More basic clinical and lab data is needed…
From Bob Gosselin: Any
From Bob Gosselin: Any underlying disease problems such as stenosis, Jak2, MDS? What is the PLT count and MPV? Patient race? Any meds, either prescribed or OTC; herbals or supplements? Malabsorption? Prior bleeding history? Not sure why VWF:PLT type would result in no ATP release as noted with those agonists. Any other lab data? What made them think to do PLTAGG?