vWF:Ag (F8AG) | | | |
EPIC Test Name
VON WILLEBRAND ANTIGENEPIC Code
LAB757Specimen Requirements
Plasma |
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Minimum Volume: | 2.7 mL |
Collection: | Collect using standard laboratory procedures. Tubes must be full to obtain proper blood to anticoagulant ratio or the specimen will be rejected. |
Transport: | Specimens scheduled to arrive in lab in less than 4 hours can be sent at room temperature. Specimens arriving more than 4 hours must be platelet poor specimens and need to be frozen before transport. Place in an insulated container filled with dry ice to ensure that the specimen does not thaw. |
Stability: | Room temp: 4 hours Frozen: 2 weeks at -20 C 6 months at -70 C. |
Container: | Light-blue top (3.2% sodium citrate) |
Processing/Storage: | Specimens that cannot reach the lab within the time frame should be double spun at 2500 g for 15 minutes to obtain platelet poor plasma. 0.5mL aliquots should be frozen in plastic at -20 degrees C. |
Rejection Causes: | Clotted
Insufficent Sample Volume |
Methods
Immuno-turbidimetricTurnaround Time
Specimen | Turnaround Time |
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Plasma | Testing is batched |
Reference Ranges
Immuno-turbidimetric
Age | All Range | Unit |
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0 day | 50-287 U/dL | U/dL |
1 -5 days | 50-254 U/dL | |
5 days - 1 month | 50-246 U/dL | |
1 - 3 months | 50-206 U/dL | |
3 - 6 months | 50-197 U/dL | |
>6 months | 64-140 U/dL | |
Clinical Indications
Diagnosis of von Willebrand disease. For initial workup, order with vWF activity and Factor VIII activity. Von Willebrand factor is an acute phase reactant and increases in stress, exercise, inflammation, and other acute phase reactions. Repeat testing might be necessary for the diagnosis of mild disease.Common Synonyms
von Willebrand Factor AntigenContact Information
Special Testing: (315)464-4460