von Willebrand Factor (VWF) GPIbM Activity Testing
VWF GPIbM Activity Assay
Versiti offers VWF GPIbM activity testing to measure von Willebrand factor platelet binding function.
The VWF GPIbM Activity assay measures binding of VWF to mutant GPIba without the need for ristocetin and is well correlated with the VWF:RCo assay1. The VWF GPIbM Activity assay demonstrates superior precision and sensitivity2 compared with the VWF ristocetin cofactor assay. Additionally, it is not subject to the falsely low values seen in individuals who possess the common p.D1472H polymorphism or the rare p.P1467S variant3, both of which confound the accurate diagnosis of von Willebrand disease (VWD).
Beginning Oct. 21, 2024, Versiti Diagnostic Laboratories will be adding the automated Innovance® VWF:GPIbM Assay to our clinical testing menu for clients who utilize our Hemostasis Laboratory requisition or LifePoint (formerly known as LabTest) to order testing. At this time, we are working diligently to identify a timeline for clients ordering any GPIbM testing via interface; our standard ELISA-based method will continue to be available to interface clients for patients of all ages during this time. Interfaced clients who wish to order the automated Innovance® VWF:GPIbM Assay for patients 6 months of age or older may utilize our Hemostasis Laboratory requisition or LifePoint to order testing.
Because the Innovance® VWF:GPIbM Assay is FDA approved for patients over 6 months of age, we will continue to offer our ELISA-based method exclusively for patients 0-6 months of age. The appropriate assay methodology will be automatically applied during the order entry process based upon the patient’s age at the time of sample draw and cannot be altered upon request.
With the addition of the Innovance® VWF:GPIbM Assay to our clinical testing menu, we are implementing new order codes for both the standalone VWF GPIbM Activity assay, as well as the diagnostic panels in which it is included. Additionally, sample requirements for the standalone GPIbM assay and some related panels have changed; see the chart below.
| Assay/Panel Name | Current Order Code | New Order Code | Sample Requirements |
| VWF GPIbM Activity | 1070 | 1990 | (1) 1 mL aliquot frozen citrated plasma |
| VWD Diagnostic Evaluation | 1800 | 1850 | (6) 1 mL aliquots frozen citrated plasma |
| VWF Inhibitor Profile | 1065 | 1050 | (2) 1 mL aliquots frozen citrated plasma |
| VWD Monitoring Profile | 1215 | 1230 | (3) 1 mL aliquots frozen citrated plasma |
Sources
- Geisen U, Zieger B, Nakamura L, Weis A, Heiz J, Michiels JJ, Heilman C. Comparison of von Willebrand factor (VWF) activity VWF: Ac with VWF ristocetin cofactor activity VWF: RCo. Thromb res 2014. 134: 246-50.
- Patzke J, Budde U, Huber A, Mendez A, Muth H, Obser T, Peerschke E, Wilkens M, Schneppenheim R. Performance evaluation and multicentre study of a von Willebrand factor activity assay based on GPIb binding in the absence of ristocetin. Blood Coagul Fibrinolysis 2014; 25: 860-70.
- Flood VH, Gill JC, Moratek PA, Christopherson P, Friedman KH, Haberichter SL, Hoffman RG, Montgomery RR. Gain-of-function GPIb binding ELISA assay.