von Willebrand Disease Panel with Collagen Binding Assay (CBA)

Casandra

Casandra Test Code QD55711Version 1 (DRAFT)

Performing Lab

Lab Quest DiagnosticsLab Test ID 15540CPT Codes 83520, 85240, 85245, 85246, 85247, 85730

von Willebrand Disease Panel with Collagen Binding Assay (CBA)

Also known as: vWF, VWD

Clinical Use

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Use

This panel is used in the comprehensive evaluation of suspected von Willebrand disease (VWD), offering functional and antigen assays to differentiate between quantitative and qualitative defects in von Willebrand factor. It includes tests such as von Willebrand factor antigen, VWF activity assays (ristocetin cofactor, collagen‑binding), factor VIII activity, and multimeric analysis, facilitating accurate classification of VWD subtypes including types 1, 2A, 2B, 2M, 2N, and type 3.

Special Instructions

For this panel, clinicians must submit separate frozen aliquots for each special coagulation assay. Blood should be collected in light blue‑top (3.2% sodium citrate) tubes, inverted gently, centrifuged promptly (first spin 15 minutes at 1500 g within 1 hour, second spin to obtain platelet‑poor plasma), transferred into plastic vials, frozen immediately, and transported on dry ice. Whole blood refrigeration prior to processing may cause cryoprecipitate formation leading to false low results.

Limitations

Improper specimen handling—such as delayed processing, refrigeration before centrifugation, or inclusion of buffy coat—can lead to cryoprecipitate formation, resulting in falsely low measurements for factor VIII and von Willebrand factor tests. Additionally, fresh‑sample‑required assays like ristocetin cofactor have constraints, making central lab processing of frozen plasma advantageous yet requiring careful workflow coordination.

Test Details

Methodology

Immunoassay (Multiplex Protein Panel)

Biomarkers

5 components

von Willebrand Factor Antigen • Multiplex Protein PanelRistocetin Cofactor Activity • Multiplex Protein PanelCollagen Binding Assay • Multiplex Protein PanelFactor VIII Activity • Multiplex Protein Panel+1 more

Result Turnaround Time

Not provided.

Specimen

Plasma

Volume

Not provided

Minimum Volume

Not provided

Container

light blue‑top tube (3.2% sodium citrate), 4 separate tubes of ~1 mL plasma each

Collection Instructions

Draw blood into light blue‑top (3.2% sodium citrate) tubes, invert gently 3‑4 times. Centrifuge 15 minutes at 1500 g within 1 hour of collection; remove plasma carefully avoiding buffy layer, transfer to new plastic vial and centrifuge again to produce platelet‑poor plasma; freeze immediately.