Test Directory

von Willebrand Factor Antigen, Plasma

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Updated Test Information:

Test Description
von Willebrand Factor Antigen, Plasma
von Willebrand Factor Ag
Test ID
General Information
Useful for:
Diagnosis of von Willebrand disease (VWD) and differentiation of VWD subtype (in conjunction with von Willebrand factor ristocetin cofactor activity and factor VIII coagulant activity)
Differentiation of VWD from hemophilia A (in conjunction with factor VIII coagulant assay)
Monitoring therapeutic efficacy of treatment with DDAVP (desmopressin) or von Willebrand factor (VWF) concentrates in patients with VWD
Specimen Type
Specimen Requirements
Light Blue
Frozen 14 days
Unacceptable Specimen Conditions
Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Latex Immunoassay (LIA)
Estimated TAT
1-3 days
Testing Schedule
CPT Code(s)
Minimum Sample Volume
0.5 mL
Reference Range


Note: Individuals of blood group "O" may have lower plasma von Willebrand factor (VWF) antigen than those of other ABO blood groups, such that apparently normal individuals of blood group "O" may have plasma VWF antigen as low as 40% to 50%, whereas the lower limit of the reference range for individuals of other blood groups may be 60% to 70%.

Children: Neonates, infants, and children have normal or mildly increased plasma VWF antigen, with respect to the adult reference range.

Performing Lab
LOINC Code(s)