Specimen Requirements

Minimum Specimen Requirements

Days Performed

Tue - Fri

Turnaround Time

1 - 3 days

Methodology

Reference Range

Clinical Info

Von Willebrand disease (VWD) is the most common inherited bleeding disorder with a prevalence of approximately 1% in the general population. The revised classification of VWD identified two major categories, quantitative and qualitative defects. The quantitative VWF defects include type 1 (partial deficiency of VWF) and type 3 (complete absence of VWF) in plasma and/or platelets. The qualitative VWF defects include type 2, which is further classified as 4 subtypes by different pathophysiologic mechanisms. Accurate laboratory diagnosis and classification of VWD are crucial because the presenting biological activitiy of VWF determines both the hemorrhagic risk and subsequent clinical managment. The collagen binding activity (CBA) assay has been proposed as a supplemental test for VWF activity. The CBA assay is based on the ability of multimeric forms of VWF to bind collagen and its greatest strength lies in the ability to selectively detect primarily high molecular weight (HMW) forms of VWF, which are known to be most functional and adhesive. The CBA assay is a useful adjunctive to diagnose VWD, and differentiate VWD with deficiency of HMW multimer forms in type 2A and type 2B from type 1. It can also differentiate very low levels of VWF in severe type 1 from complete absence of VWF in type 3. It has been reported as a better marker for therapeutic efficacy of treament with DDAVP (desmopressin) and FVIII concentrate.

Technical Brief

• Collagen Binding Activity Assay for Von Willebrand Disease