von Willebrand Factor Collagen Binding Assay

Test Code

VWFCB

Quest Code

10924

CPT Codes
83520

Preferred Specimen

1 mL frozen plasma collected in a 3.2% sodium citrate (light blue-top) tube

Minimum Volume

0.5 mL

Transport Temperature

Frozen

Specimen Stability

Room temperature: 24 hours
Refrigerated: 24 hours
Frozen: 21 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Lipemic • Hemolyzed or icteric plasmas

Methodology
Enzyme Linked Immunosorbent Immunoassay (ELISA)

FDA Status
This test was performed using a kit that has not been cleared or approved by the FDA. The analytical performance characteristics of this test have been determined by Quest Diagnostics. This test should not be used for diagnosis without confirmation by other medically established means.

Setup Schedule

Set up: Mon, Wed; Report available: 3-8 days

Reference Range

vWf:Collagen Binding	45-198 %normal
Ratio (CBA/vW Ag)	≥0.50 ratio

A CBA:vWF AG ratio of <0.5 suggests a qualitative defect of von Willebrand Factor.

References:
1) Favaloro, EJ et. al. Discrimination of von Willebrand's disease (VWD) subtypes: direct comparison of von Willebrand factor: collagen binding assay (VWF:CBA) with monoclonal antibody (MAB) based vWF-capture systems. Thromb. Haemost. 2000;84:541-547.

Clinical Significance

The Collagen Binding Activity is a surrogate assay for the measurement of von Willebrand Factor (VWF) mediated Platelet adhesion. Decreased activity (collagen bound to the A3 domain of the VWF protein) relative to the VWF antigen level, is observed with qualitative defects of VWF (type 2 disorders). The CBA assay may assist in the discrimination of type 2 disorders. In addition, there have been reports of isolated defects of CBA as a cause for a variant form of von Willebrand disease.

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

Last Updated: April 2, 2018

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.