von Willebrand Factor Ag

Test Code

30891

CPT Codes
85246<br>Limited Access Code

Preferred Specimen

1 mL plasma collected in 3.2% sodium citrate (light blue-top) tube

Minimum Volume

0.5 mL

Instructions

Platelet Poor Plasma: 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 WBS/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.

Hemolyzed specimens are not acceptable.

Note: Storage of whole blood at refrigerated temperature prior to processing may lead to cryoprecipitate formation and falsely low Factor VIII and von Willebrand Factor studies.

Refer to Quest Diagnostics Directory of Service under Specimen Collection section, Coagulation Testing, for further information on specimen processing.

Transport Container

Plastic vial

Transport Temperature

Frozen

Specimen Stability

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

Methodology
Immunoturbidimetric

Setup Schedule

Set up: Mon-Fri; Report available: Next day

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.

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.