VWPR - Specimen: von Willebrand Profile

Test Catalog

Take Our Survey

Test ID: VWPR    
von Willebrand Profile

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

Initial testing includes: coag factor VIII activity assay, von Willebrand factor (VWF) antigen, and VWF activity.  

If the factor VIII, VWF antigen, and VWF activity are normal, and VWF activity:VWF antigen ratio is > or =0.8, a computer-generated interpretive comment indicating no evidence of von Willebrand’s disease will be provided.

If VWF activity assay is <55%, VWF ristocetin cofactor activity assay will be performed. If VWF antigen is <55%, the VWF activity is <55%, or the VWF activity:VWF antigen ratio is <0.8, VWF multimer analysis will be performed.

If any test results are abnormal, all results will be reviewed by a coagulation consultant and a Special Coagulation Consultant Interpretation will be provided.

 

See von Willebrand Disease Profile in Special Instructions.

Specimen Type Describes the specimen type needed for testing

Plasma Na Cit

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

See Coagulation Studies in Special Instructions.

 

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (citrate)

Submission Container/Tube: Plastic vials

Specimen Volume: 3 mL in 3 plastic vials each containing 1 mL

Collection Instructions:

1. Specimen must be drawn prior to factor replacement therapy.

2. Spin down, remove plasma, and spin plasma again.

3. Freeze specimens immediately at < or =-40 degrees C, if possible.

4. Send specimens in the same shipping container.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. If priority specimen, mark request form, give reason, and request a call-back.

3. Each coagulation assay requested should have its own vial.

4. If multiple coagulation profiles are ordered, each profile must be on a separate order.

Forms:

1. Coagulation Patient Information Sheet (T675) in Special Instructions

2. If not ordering electronically, complete, print, and send a Coagulation Test Request Form (T753) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/coagulation-test-request-form.pdf)

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

2 mL in 2 plastic vials each containing 1 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK: Gross reject

Other

NA

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
Plasma Na CitFrozen14 days

Key