VWF is a multimeric high molecular weight (HPM) glycoprotein involved in primary hemostasis. VWF protects FVIII from degradation and transports it to plasma, and mediates platelet activation by binding to their membrane receptors GPIb and GPIIb / IIIa.
A quantitative or qualitative defect of VWF causes hemorrhagic pathologies which can be acquired or hereditary. VWF assay is needed to determine the type of disease.
HPM forms of VWF preferentially bind to collagen than low molecular weight forms.
The binding capacity of VWF to collagen serves as a parameter to determine the adhesive properties of VWF thus reflecting its physiological properties.
A decrease in collagen binding can be due to :
- a decrease in the rate of VWF (type 1 and type 3 VWD)
- an absence of HPM multimer (type 2A and 2B VWD) : a rare specific deficiency in collagen binding is classified as type 2M.
- Reflects the physiological activity of VWF in plasma and concentrates. (Specialized hemostasis)
- Marker of response to DDAVP.
- Detects high concentrations of VWF from HPM in PTT (Thrombotic Thrombocytopenic Purpura).
- Detects low concentrations of low molecular weight VWF in TE (Essential Thrombocythemia).
- Sensitivity : 0 - 1.3 IU / mL
- Stability 6 months after opening.
- Reaction time 60 minutes.
- Better reproducibility.
- Better sensitivity.
- Better correlation with the HPM forms of VWF.
- Better sensitivity in detecting low amounts of VWF in severe type 1 deficiency.
- 12 breakable ELISA strips of 8 wells coated with type I collagen
- 1 vial x conjugated antibody concentrate (0.3 mL)
- 1 vial x TMB chromogen (12 mL)
- 1 bottle x stop solution (12 mL)
- 1 vial x wash buffer concentrate (80 mL)
- 1 vial x incubation buffer (90 mL)
- 5 vials x freeze-dried calibrators
- 1 vial x lyophilized low control plasma
- 1 vial x lyophilized high control plasma
- 2 adhesives for ELISA plate