von Willebrand Factor Antigen, Plasma

Casandra

Casandra Test Code MC19729Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID VWAGCPT Code 85246

von Willebrand Factor Antigen, Plasma

Clinical Use

Use

The von Willebrand Factor Antigen test is crucial for diagnosing von Willebrand disease (VWD) and distinguishing between its subtypes alongside the ristocetin cofactor activity and factor VIII coagulant activity assays. It also assists in differentiating VWD from hemophilia A and monitors the effectiveness of von Willebrand factor concentrates and DDAVP treatments in VWD patients.

Special Instructions

For optimum results, this test should be used with von Willebrand factor ristocetin cofactor activity and factor VIII coagulant activity tests. For a comprehensive diagnostic approach, considering a panel of tests with reflexive testing and interpretive reporting is recommended. Each coagulation assay requested should be in its own vial, and it's crucial to follow proper specimen handling and processing guidelines to prevent platelet contamination.

Limitations

Lipemic specimens can lead to underestimation, and rheumatoid factor can cause overestimation of von Willebrand Factor levels. Being an acute-phase reactant, von Willebrand Factor levels can naturally be elevated due to conditions like inflammation, stress, and pregnancy, which may complicate diagnosing mild forms of VWD. Hence, normal low levels don't rule out VWD, especially for blood group 'O' individuals. Proper handling and repeat testing are advised when necessary.

Test Details

New York Approved