Posted Date
Effective Date
Update Type New Tests
Order Code VWFGP



von Willebrand Factor GPIbM Activity

Order Code:                  VWFGP

Fee Code:                     BA021 (CPT 85397)


MLabs Coagulation Laboratory will begin offering von Willebrand Factor GPIbM Activity by ristocetin-independent latex bead assay using recombinant gain-of-function GPIbα subunit effective February 20, 2023.  This test replaces the current von Willebrand Factor Activity assay (order code VWF) for use as an aid in the diagnosis of von Willebrand disease and as a component of the von Willebrand Disease Panel (order code VWD). 


Note that order code VWF will remain active for use by MLabs Coagulation clinical consultants in limited circumstances.   Interfaced clients should update test mappings from VWF to VWFGP.


Collection Instructions: Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.


Reference Range: 50 – 200%