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vWF:Ag (F8AG)

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EPIC Test Name

VON WILLEBRAND ANTIGEN

EPIC Code

LAB757

Specimen Requirements

Plasma
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-turbidimetric

Turnaround Time

SpecimenTurnaround Time
PlasmaTesting is batched

Reference Ranges

Immuno-turbidimetric
AgeAll RangeUnit
0 day50-287 U/dLU/dL
1 -5 days50-254 U/dL
5 days - 1 month50-246 U/dL
1 - 3 months50-206 U/dL
3 - 6 months50-197 U/dL
>6 months64-140 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 Antigen

Performed

Lab
Special Testing

CPT

85246

LOINC

6012-9

Contact Information

Special Testing: (315)464-4460
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