von Willebrand Disease Type 2N (vWF: Factor VIII)

Test Code
70068

CPT Codes
83520

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

Patient Preparation
A patient must not be given any recombinant vWF or vWF concentrates before to testing

Minimum Volume
0.5 mL

Instructions
Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approx. 1500 x 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.
Please call the lab for additional setups if results need to be expedited.

Transport Temperature
Frozen

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 21 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Contaminated specimens • Grossly hemolyzed • Lipemic • Improperly stored or handled specimen

Methodology
Immunoassay (IA)

Setup Schedule
Set up: As needed, at least once a month; Report Available: Within 2 days after set up

Reference Range
0.73-1.42 ratio

Clinical Significance
To differentiate between hemophilia A, hemophilia A carrier state, and type 2N vWD. The Type IIN vWD is assocoated with mild to moderate FVIII deficiency and otherwise normal von Willebrand Antigen and Ristocetin Cofactor.

Performing Laboratory
Quest Diagnostics Nichols Inst San Juan Capistrano
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130



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.