LOINC display name : vWf ristocetin cofactor act/vWf Ag (PPP) [Ratio];
LOINC long common name : von Willebrand factor (vWf) ristocetin cofactor/von Willebrand factor (vWf) Ag [Ratio]
in Platelet poor plasma;
LOINC short name : vWf:RCo/vWF Ag PPP-Rto;
LOINC description : This term represents a ratio of two results that are expressed as percentages of normal:
the von Willebrand factor.ristocetin cofactor activity and the von Willebrand factor
antigen concentration, both of which are reported as actual/Normal. The von Willebrand
factor (vWF) ristocetin cofactor activity to antigen ratio can help distinguish different
types of von Willebrand disease (VWD). VWD types 1 and 3 are usually associated with
a quantitative decrease in vWF, which would affect both the vWF ristocetin cofactor
activity as well as vWF antigen concentration, while type 2 is associated with a functional
defect in VWF, which would affect the activity but not the amount of antigen present.
Therefore, patients with type 2 VWD are likely to have a lower vWF ristocetin cofactor
activity to antigen ratio (less than 0.6-0.7) compared to patients with types 1 or
3 VWD.;
Has component