DETECTION OF VON-WILLEBRAND FACTOR (vWF) ACTIVITY

Abstract

The present invention relates to a method for detecting von-Willebrand factor (vWF) activity comprising assaying a sample in the presence of a soluble form or portion of glycoprotein Ib(α) (GPIb(α)) and ristocetin, or a functionally equivalent substance. Additionally, the invention relates to the use of the aforementioned soluble form or portion of glycoprotein Ib(α), of ristocetin or a functional equivalent substance, of specifically reacting anti-GPIB(α) antibody(ies) and/or of specific binding partners, like specifically reacting anti-vWF antibody(ies) for carrying out the method of the invention. Furthermore, the present invention relates to kits for carrying out the method of the invention.

1 .- 2 . (canceled) 
   
   
       3 . A kit for determining von Willebrand factor (vWF) ristocetin cofactor activity, comprising:
 a soluble form or portion of glycoprotein 1bα (GP1bα) that is not associated with a platelet;   an anti-GP1bα antibody bound to a solid support;   an anti-von Willebrand Factor (WF) antibody; and   ristocetin or a functionally equivalent substance.   
   
   
       4 . The kit of  claim 3 , wherein said solid support is selected from the group consisting of plastic, glass, silicon, metal, polystyrene, polyvinyl chloride, polypropylene, polyethylene, polycarbonate, dextran, nylon, amylase, natural or modified cellulose, polyacrylamide, agarose, magnetite and combinations thereof. 
   
   
       5 . The kit of  claim 4 , wherein said solid support comprises a latex bead. 
   
   
       6 . The kit of  claim 3 , wherein said anti-GP1bα antibody is a monoclonal antibody, a polyclonal antibody, a synthetic antibody, or a fragment of an antibody. 
   
   
       7 . The kit of  claim 3 , wherein said anti-vWF antibody is a monoclonal antibody, a polyclonal antibody, a synthetic antibody, or a fragment of an antibody. 
   
   
       8 . The kit of  claim 3 , wherein said anti-vWF antibody is detectably labeled. 
   
   
       9 . The kit of  claim 8 , wherein said detectable label is a tag, a fluorescent marker, an enzyme, a particle or a radioactive marker. 
   
   
       10 . The kit of  claim 9 , wherein said detectable label is a chemiluminescent compound. 
   
   
       11 . The kit of  claim 3 , wherein the soluble form or portion of GP1bα is a recombinant polypeptide. 
   
   
       12 . The kit of  claim 3 , wherein the soluble form or the portion of GP1bα comprises an N-terminal domain of GP1bα. 
   
   
       13 . The kit of  claim 3 , wherein the soluble form or the portion of GP1bα comprises amino acid residues His1-Val289 of GP1bα. 
   
   
       14 . The kit of  claim 3 , further comprising a standard comprising predetermined amounts of vWF.