Test ID: VWFX
von Willebrand Factor Activity, Plasma
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Yes
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/83099 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 ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| RIST | Ristocetin Cofactor, P | No | No |
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
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
von Willebrand Factor Activity, P
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