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von Willebrand Disease Panel without Collagen Binding Assay (CBA)
Test CodeCPT Codes
85240, 85245, 85246, 85247, 85730
Includes
Factor VIII Activity, Clotting
Ristocetin Cofactor
von Willebrand Factor Antigen
von Willebrand Antigen Multimeric Analysis
Preferred Specimen
Minimum Volume
0.75 mL (x4)
Instructions
Please submit a separate, frozen vial for each special coagulation assay ordered. Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Freeze immediately and transport on dry ice.
Note: Storage of whole blood at refrigerated temperatures prior to processing may lead to cryoprecipitate formation and falsely low Factor ViII and von Willebrand Factor studies.
Transport Temperature
Specimen Stability
Refrigerated: Unacceptable
Frozen: 14 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
See individual assays
Methodology
See individual tests
FDA Status
von Willebrand Antigen, Multimeric Analysis: This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Clinical Significance
This panel may be used to help diagnose von Willebrand disease (VWD) and categorize disease subtype.
von Willebrand factor (VWF) is a blood coagulation protein that has 2 functions: (1) mediating platelet adhesion to the injured endothelium and (2) acting as a protective carrier protein for coagulation factor VIII. Deficiency of VWF causes VWD, the most common inherited bleeding disorder that affects approximately 1 in 1,000 individuals at the primary care level [1]. VWD is classified into type 1 (quantitative deficiency of VWF), type 2 (qualitative deficiency of VWF), and type 3 (total absence of VWF). Different types of VWD are further categorized into subtypes, identification of which is important to inform prognosis and treatment decisions.
Three tests are recommended for initial diagnosis of VWD [2]: VWF antigen, platelet-dependent VWF activity (eg, ristocetin cofactor), and factor VIII activity. Additional tests may be needed to further identify the subtype of VWD. VWF multimer analysis is also included in this panel and is useful for discriminating between VWD type 2M from 2A/2B and platelet-type VWD [1].
Test results of acquired von Willebrand syndrome (AVWS) may be similar to those of congenital VWD [1, 2]. However, patients with AVWS do not have a family history of bleeding or a personal life-long history of bleeding. Conditions associated with AVWS include lymphoproliferative disorders, monoclonal gammopathy of undetermined significance, Wilms tumor expressing GPIb, myeloproliferative disorders, aortic stenosis, ventricular assist devices, and hypothyroidism.
The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.
References
1. James PD, et al. Blood Adv. 2021;5(1):280-300.
2. Higgins RA, et al. Platelets and van Willebrand factor. In: Rifai R, et al, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier Inc; 2022.
