Collagen Binding Assay (VWF:CB)

Coagulation

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Description

Von Willebrand disease (VWD) is a bleeding disorder caused by a reduction or dysfunction of Von Willebrand factor (VWF). VWF is a large multimeric glycoprotein which circulates in the plasma as a series of polymers called multimers. High molecular weight multimers are important for binding to collagen and platelet receptors during primary haemostasis to facilitate wound healing. Von Willebrand Factor (VWF) has three functions in haemostasis; as a carrier protein for FVIII, as a bi-functional ligand, mediating platelet GP1b adhesion to collagen, and for platelet to platelet adhesion. There are at least 16 types of collagen but the four main types are types I, II, III and IV. The routine assay for collagen binding to high molecular weight multimers of VWF is by ELISA methodology using human placental type III collagen.

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Indications

Collagen binding to VWF is assessed in patients with possible VWD. The measurement of Collagen binding is to determine the adhesive properties of VWF. The ability to bind collagen correlates with VWF activity and is a useful test in measuring the physiological function of VWF, aiding the diagnosis of von Willebrand disease. A reduced collagen binding may indicate types 1, 2A, 2B and 3 VWD. The VWF:CB level is often very similar to the VWF activity, however there are a few cases reported with reduced VWF:CB in the presence of normal VWF activity and multimer pattern.

Reduced levels of VWF:CBA may also be associated with blood group O. Raised levels are associated with age, pregnancy, physical exercise, ethnic group and the use of the oral contraceptive pill.

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Sample Type

2 x 0.5ml citrated plasma aliquots or plasma (Citrate 2.7ml Blue) x 2

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Reference Range

Reference range is indicated on the report.

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Turnaround Time

Within 5 weeks

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Testing Frequency

Monthly

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External Notes

The accuracy of all coagulation tests is greatly influenced by pre analytical variables. It is essential that sample quality is given the highest of priorities. Samples which fail to meet quality criteria including age of sample, specimen fill (>90%), haemolysed, clotted or activated samples will be rejected and a repeat sample requested.

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References

Favaloro EJ ( 2002 ). VWF collagen binding activity assay in the diagnosis of VWD: a 15 year journey. Sem Thromb Haemost, 28, 191-202
Favaloro EJ. Utility of the von Willebrand factor collagen binding assay in the diagnosis of von Willebrand disease. Am J Hematol. 2017;92(1):114–118. doi:10.1002/ajh.24556
Riddell AF, Gomez K, Millar CM, et al. Characterization of W1745C and S1783A: 2 novel mutations causing defective collagen binding in the A3 domain of von Willebrand factor. Blood. 2009;114(16):3489–3496. doi:10.1182/blood-2008-10-184317

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See Also

FVIII complex
VWF Antigen

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.