Von Willebrand Panel

Additional Info: Test includes APTT, VWF (R:CO), VWF antigen, factor VIII activity, VW antigen-Multimeric analysis

Useful For:
Von Willebrand’s disease (vWD) is perhaps the most common bleeding disorder known but the diagnosis can only be assured by performing a multiplicity of tests to #1-confirm the diagnosis; #2-be able to distinguish Type I, Type II, and Type III disease types, which require different treatment programs. Therefore it is essential to measure FVIII activity along with vWF Antigen, Functional vWF Activity by Ristocetin Cofactor and measure Multimeric analysis of von Willebrand Protein to characterize intermediate and high Weight forms.

PTT is a screening test for deficiencies of plasma coagulation factors other than Factors VII and XIII. This test is also used to monitor patients on heparin therapy.

Factor VIII bleeding disorders may be due to inherited or acquired deficiencies of a clotting factor.

Ristocetin cofactor is useful in assessing binding of von Willebrand Factor to platelet factor GP1b. When combined with other tests, results are useful in categorizing the type of von Willebrand disease.

Methodology: Multiple methodologies

Specimen Requirements: 3 blue-top (citrate) tubes (minumum: the remaining platelet poor plasma separated from 2.7 mL whole blood OR 0.75 mL x4). Centrifuge blue-top soon after collection. Separate plasma and FREEZE immediately. Send specimen frozen in plastic vial.

NOTE:
If using a butterfly collection set, fill a 1 mL waste tube prior to blue-top. This ensures full blood volume in blue-top.
Tube must be filled to capacity.
Draw specimen by vacuum. Do not over-fill the tube.
Hemolyzed specimens are not acceptable.

Analytical Time: 5 days

Days Set Up: Monday through Friday

CPT Information:
85247 VWF; multimetric analysis 85240 factor VIII activity 85245 VWF (R:CO) function 85246 VWF antigen 85730 APTT