|Profile or Test Panel||
Bleeding Diathesis with a Normal aPTT/PT Profile
|Indications||Requires VW Activity by Ristocetin Cofactor and FVIII levels to interpret results|
|Test Information||Immunoreactive plasma vWF:Ag is determined by ELISA using a polyclonal antibody to human vWF. Levels are generally mildly (Type 1) or markedly (Type 3) reduced in von Willebrand disease. Relatively normal antigen level may accompany reduced functional VWF in patients with Type 2 variants of von Willebrand disease. Values are also affected by ABO blood type, with type O averaging 15-30% lower than non-O.|
|Additional Test Information||Normal ranges are included on testing report and can be made available upon request.|
|Sample Requirements||Whole Blood: 3.2% sodium citrated (blue top) OR
|Requested Volume||Two 5 ml 3.2% sodium citrated (blue top) tubes as whole blood OR
frozen plasma in 4 X 1mL aliquots in plastic tubes.
|Sample Information||Whole blood is preferred for testing, but if it is not possible to send whole blood tubes TO ARRIVE HERE WITHIN 2 HOURS of collection, then send frozen plasma. To prepare plasma, centrifuge blue top tubes at 1500g for 15 minutes and remove the plasma and centrifuge a second time at 1500g for an additional 15 minutes. Aliquot approximately 1 ml of plasma into 4 plastic tubes, and freeze.|
|Shipping Information||Whole Blood: Send at ambient temperature (18-25°C) and must be received within the lab in less than or equal to 2 hours after collection.
Frozen Plasma: Send on dry ice
Send samples to:
For additional information, please see Ordering Information
|Requisition Form||RFT- Hemostasis Reference Laboratory|
|Turn around Time (analytic time)||3 Business Days|
|Report/Results||Fax number required to receive report|