Von Willebrand Panel

Orderable EAP code:

LAB00266

Billable EAP Codes:

80001094 x 1 (Factor VIII Coag)
80001090 x 1 (Factor VIII: VWF AG)
80001088 x 1 (Von Will/RAF)

CPT Codes:

85240 x 1 (Factor VIII Coag)
85246 x 1 (Factor VIII: VWF AG)
85397 x 1 (Von Will/RAF)

Lab Section:

Hemostasis and Thrombosis

Includes:

Factor VIII Activity, Von Willebrand Factor Activity, Von Willebrand Antigen

Turnaround Time:

1 to 3 days

Test Schedule:

Factor VIII Activity = 7 days a week, performed at Core Lab.
Von Willebrand Factor Activity, Von Willebrand Antigen = Monday, Wednesday, Friday.

Critical Values:

See individual tests. 

Specimen Requirements:

Four full 2.7 mL LIGHT BLUE top tubes, 3.2% sodium citrate.  Specimens must be processed and frozen within 2 hours of specimen collection.

Send 4- 1ml aliquots of platelet poor plasma, samples must remain frozen during storage and shipment. 

Stability is 14 days at -20°C or at -70°C for up to 12 months. 

Detailed specimen collection and processing instructions are located under Lab Sections and then the Hemostasis and Thrombosis (Opens in a new window) section.

Pediatric Specimen Requirements:

Two full pediatric 1.3 mL LIGHT BLUE top tubes, 3.2% sodium citrate. Specimens must be processed and frozen within 2 hours of specimen collection. 

Send 2- 600 uL aliquot of platelet poor plasma, samples must remain frozen during storage and shipment. 

Stability is 14 days at -20°C or at -70°C for up to 12 months. 

For pediatric patients requiring multiple coagulation tests, please call 503-494-7383 regarding draw volumes.

Reference Range:

See individual tests.
For children less than 6 months, see link to published reference ranges (Opens in a new window).

Comments:

This test is used in the diagnosis and classification of von Willebrand disease.

The von Willebrand factor (vWF) is absent or decreased in individuals with von Willebrand disease (vWD). vWF activity is the functional measure of the factor VIII molecule that is necessary for the agglutination of platelets observed in the presence of ristocetin. Since many variants of vWD exist, the yield of identifying patients with this disease is enhanced if all three of the following are assayed: factor VIII activity, von Willebrand factor antigen (vWF:Ag), and vWF-RCT activity. Because many patients with vWD have mild disease, repeated testing may be necessary to diagnose this disorder. Normal values do not exclude vWD. Female patients with vWD on oral contraceptives or who are pregnant may have normal values. Von Willebrand factor is also an acute-phase reactant and is elevated with stress or exercise.

Methodology: Refer to specific assays.

High doses of standard heparin (greater than 1.0 U/mL) may interfere with a PT mixing study. Anti-Xa agents such as Rivaroxaban may also interfere with PT mixing studies. Clinical correlation is advised.

Synonyms:

Von Willebrand