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von Willebrand Comprehensive Panel 2 with Consultation [19681X]
Test Code3948551
CPT Codes
83520, 85240, 85245, 85246, 85247, 85730<br>Dependent on the complexity of the consultation, 80503 or 80504 or 80505 may be assigned. 80506 may also be billed if high complexity with more than 60 minutes
Includes
Partial Thromboplastin Time, Activated
Factor VIII Activity, Clotting
von Willebrand Factor Antigen
Ristocetin Cofactor
von Willebrand Factor Collagen Binding Assay
von Willebrand Antigen, Multimeric Analysis
Coagulation Consultation
Factor VIII Activity, Clotting
von Willebrand Factor Antigen
Ristocetin Cofactor
von Willebrand Factor Collagen Binding Assay
von Willebrand Antigen, Multimeric Analysis
Coagulation Consultation
Preferred Specimen
1 mL (x4) frozen platelet-poor plasma collected in 3.2% sodium citrate (light blue-top) tubes
Minimum Volume
0.75 mL (x4)
Instructions
See individual tests for specific specimen requirements and stabilities.
Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes 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 four new plastic vials. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship 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.
Platelet-poor plasma: Centrifuge light blue-top tube 15 minutes at approximately 1500 g within 60 minutes 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 four new plastic vials. Plasma must be free of platelets (<10,000/mcL). Freeze immediately and ship 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 Container
Transport tube (x4)
Transport Temperature
Frozen
Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days
Refrigerated: Unacceptable
Frozen: 14 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
See individual assays
Methodology
See individual assays
Setup Schedule
Set up and Report available: See individual assays
Reference Range
See Laboratory Report
Clinical Significance
This test 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 and collagen binding activity are included in this panel and are useful to discriminate between VWD subtype 2A/2B from 2M and rare forms of 2M [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.
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 and collagen binding activity are included in this panel and are useful to discriminate between VWD subtype 2A/2B from 2M and rare forms of 2M [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.
