VWFX - Overview: von Willebrand Factor Activity, Plasma

Test Catalog

Test ID: VWFX    
von Willebrand Factor Activity, Plasma

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis of von Willebrand disease (VWD) and differentiation of VWD subtypes or differentiation of VWD from hemophilia A (Note: this activity assay is most effective when it is combined with measurement of von Willebrand factor (VWF) antigen and factor VIII coagulant activity, preferably as a panel of tests with reflexive testing and interpretive reporting [eg, VWPR / von Willebrand Profile])


Monitoring therapeutic efficacy of treatment with DDAVP (desmopressin) or VWF concentrates in patients with VWD

Reflex Tests Lists test(s) that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial test(s)

Test IDReporting NameAvailable SeparatelyAlways Performed
RISTRistocetin Cofactor, PNoNo

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

If von Willebrand factor activity is <55%, then the von Willebrand factor ristocetin cofactor activity assay will be performed at an additional charge.

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test

Latex Particle Enhanced Immunoassay

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

von Willebrand Factor Activity, P

Aliases Lists additional common names for a test, as an aid in searching

Von Willeband factor activity
Ristocetin cofactor
VFW Activity