VWF Collagen IV Binding

von Willebrand Factor Collagen Binding

The next evolution in von Willebrand Disease (VWD) diagnostics, Versiti’s novel Collagen IV Binding Assay, is now available for clinical order. In vivo, collagen binding by VWF facilitates platelet adhesion at sites of blood vessel injury. The Collagen III Binding (VWF:CB3) (order code: 1281)  and Collagen IV Binding (VWF:CB4) (order code: 1280) assays are supplemental functional assays that specifically evaluates the ability of a patient’s VWF to support platelet adhesion.

Discrepancy between Collagen IV Binding  and VWF antigen levels in the absence of a multimer defect could indicate type 2M VWD due to defect in the A1 domain. Similarly, discrepancy between Collagen III Binding  and VWF antigen levels is a sensitive screen for deficiency of large VWF multimers, but if multimer distribution is normal, could indicate type 2M VWD due to defect in the A3 domain.

Additionally, Versiti is pleased to offer the Collagen Binding Profile (order code: 1279), designed to identify rare individuals with isolated defects in the A3 domain that binds type I and III collagen, and even rarer individuals with defects in the A1 domain that binds types IV and VI collagen.

Indications for testing:

• VWF Collagen III Binding and/or VWF Collagen IV Binding:

  Supplemental study where the result will be correlated and interpreted considering a locally determined VWF antigen result. (Note that Versiti lab reference intervals for VWF:CB3/VWF:Ag and VWF:CB4/VWF:Ag may not be fully translated if the VWF:Ag is determined locally).

• VWF Collagen Binding Profile (includes VWF:Ag, VWF:CB3 and VWF:CB4):
  Supplemental investigation of a patient with a hemorrhagic disorder in whom initial studies do not fully explain the bleeding phenotype, and evaluation for rare forms of type 2M VWD merit investigation.