Test ID: VWFX
von Willebrand Factor Activity, Plasma
Secondary ID
A test code used for billing and in test definitions created prior to November 2011
89792
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 | Secondary ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|---|
| RIST | 9046 | Ristocetin Cofactor, P | Yes | 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


