Patent ID: 7622259

Claim:
A method for discriminating between types of von-Willebrand disease using a von-Willebrand factor (vWF) binding activity, the method comprising the steps of: (a) detecting the binding activity of vWF in a sample to a soluble form or a portion of glycoprotein 1b(α) (GP1b(α)) that is not associated with a platelet in the presence of ristocetin or a functionally equivalent substance, wherein the soluble form or portion of GP1b(a) is presented by an anti-GP1b(α) antibody; (b) determining an amount of vWF-antigen in said sample; (c) determining a ratio between the binding activity detected under step (a) and the amount of vWF-antigen determined under step (b) for said sample; (d) comparing the ratio obtained under (c) to a reference range; and (e) discriminating between types of von-Willebrand disease based using the comparison result obtained under step (d).