Von Willebrand Disease (VWD) is the most common inherited bleeding disorder. Clinically, it is often characterized by muco-cutaneous hemorrhages. The Group test includes Factor VIII Assay, vWF Activity and Antigen.
The 9:1 blood/citrate ratio must be kept constant. Adjustments for the amount of anticoagulant should be made when the hematocrit is abnormal (above 55%). Mix immediately to prevent clotting.
Collection Instructions
Send whole blood sample(s) at room temperature as soon as possible.
If specimens cannot be shipped immediately, centrifuge and separate plasma within 1 hour of collection, send frozen plasma on dry ice
8 hrs at Room Temperature, 12 months at -70ºC or below.
Test may be requested at any time. Samples are aliquotted and frozen. The assay is run in batches.
Special arrangements made with Lab
1-2 weeks
See individual ranges and values for Factor VIII Assay, vWF Activity and Antigen. In case of discrepancies, always interpret results using reference ranges as stated on laboratory reports and/or electronic patient chart.