How are specimens collected for von Willebrand factor (vWF) multimer analysis?

Updated: Aug 01, 2019
  • Author: Carlos Solano Loran, MD; Chief Editor: Eric B Staros, MD  more...
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Answer

Answer

Specifics for collection and panels associated with von Willebrand factor (vWF) multimers are as follows:

  • Specimen type: Platelet-poor plasma (double-centrifuged specimen)

  • Container/tube: Light-blue top (citrate)

  • Collection method: Venipuncture

  • Specimen volume: 1 mL

Other instructions are as follows:

  • Draw specimen before coagulation factor replacement therapy.

  • Spin down, remove plasma, and spin again. Double centrifugation is essential for accurate results as platelet contamination may affect the assay.

  • Preferably, freeze specimen immediately to 40°C or less. Frozen specimens remain stable for 42 days. [3]

  • vWF antigen, vWF activity, and factor VIII activity are required before performing this test. Submit separate specimens for the previously mentioned assays following their specific specimen requirements.

  • Reject the specimen only if gross lipemia, hemolysis, or bilirubinemia is present.


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