von Willebrand Factor Antigen

Message
This test is also available in Menorrhagia Screen test codes 19649X and 19651X. This test is also available in von Willebrand Panels 19790X, 19681X, 19735X.

Test Code
VWFA

CPT Codes
85246

Preferred Specimen
1 mL frozen platelet poor plasma collected in 3.2% sodium citrate (light blue-top) tube

Minimum Volume
0.5 mL

Instructions
Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcl). Freeze immediately and ship on dry ice. Note: Storage of whole blood at refrigerated temperatures prior to processing may lead to cryoprecipitate formation and falsely low factor viii and von willebrand factor studies.

Transport Container
Plastic screw-cap vial

Transport Temperature
Frozen

Specimen Stability
Room temperature: 8 hours
Refrigerated: 24 hours
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Received room temperature • Received refrigerated

Methodology
Immunoturbidimetric Assay

Reference Range
50-217 %

Clinical Significance
von Willebrand Disease is the most common hereditary bleeding disorder; it may also be acquired. von Willebrand Factor is necessary for platelet adhesion to injured endothelium. von Willebrand Factor Antigen is useful in assessing the quantity of von Willebrand Factor. When combined with other tests, results are useful in categorizing the type of von Willebrand Disease.



Performed By
Quest Diagnostics Nichols Institute



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.