von Willebrand factor Ag

Keywords: von Willebrand factor antigen, VWF:Ag


4.5 mL blood added to 0.5 mL citrate.


ELISA, electroimmunoassay, immunoradiometric assay or EIA: level of VWF:Ag in test plasma expressed as a percentage of that in pooled, normal plasma.

Reference Interval:

Refer to laboratory. Generally 50-200% of the level in pooled normal plasma, sometimes expressed as 0.5-2.0 U/mL.


Investigation of a possible bleeding disorder: diagnosis of von Willebrand disease (VWD) and its variant forms.

Detection, in association with Factor VIII assay, of carriers of haemophilia A.


See von Willebrand disease testing, Ristocetin cofactor, Collagen binding assay.


Favaloro EJ. Clin Haematol. 2001; 14: 299-319.

Marder VJ et al. Thromb Haemost. 1985; 54: 871-872.