von Willebrand Disease Panel with Collagen Binding Assay (CBA)
Also known as: vWF, VWD
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.
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
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.
Storage Instructions
Freeze immediately; transport on dry ice.
Causes for Rejection
Refrigerated whole blood prior to processing (risk of cryoprecipitate) likely leads to rejection.