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HelpTest Code AVWPR von Willebrand Disease Profile, Plasma
Ordering Guidance
Multiple coagulation profile tests are available. See Coagulation Profile Comparison for testing that is performed with each profile.
Shipping Instructions
Send all 3 aliquots in the same shipping container.
Necessary Information
1. If priority specimen, mark request form, give reason, and request a call-back.
2. Note if patient is currently receiving anticoagulant treatment (eg, heparin, Coumadin [warfarin]).
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation:
1. Patient should not be receiving anticoagulant treatment (eg, warfarin, heparin). Treatment with heparin causes false-positive results of in vitro coagulation testing for lupus anticoagulant. Coumadin (warfarin) treatment may impair ability to detect the more subtle varieties of lupus-like anticoagulants.
2. Patient should also not be receiving fibrinolytic agents (streptokinase, urokinase, tissue plasminogen activator[ tPA]).
3. It is best to perform this study pretransfusion if possible. If patient has been recently transfused, wait at least 48 hours after transfusion to collect the specimen.
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vials
Specimen Volume: 3 mL in 3 plastic vials, each containing 1 mL
Collection Instructions:
1. Specimen must be collected prior to factor replacement therapy.
2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
4. Aliquot plasma (1-2 mL per aliquot) into 3 separate plastic vials, leaving 0.25 mL in the bottom of centrifuged vial.
5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Forms
1. Coagulation Patient Information (T675)
2. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Useful For
Detection of deficiency or abnormality of von Willebrand factor (VWF) and related deficiency of factor VIII coagulant activity
Subtyping von Willebrand disease (VWD) as type 1 (most common), type 2 variants (less common), or type 3 (rare)
This test is not useful for detection of hemophilia carriers.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| AVWPI | von Willebrand Disease Tech Interp | No | Yes |
| F8A | Coag Factor VIII Activity Assay, P | Yes | Yes |
| VWAG | von Willebrand Factor Ag, P | Yes | Yes |
| VWACT | von Willebrand Factor Activity, P | Yes | Yes |
Testing Algorithm
Initial testing includes coagulation factor VIII activity assay, von Willebrand factor (VWF) antigen, VWF activity and interpretation.
If the factor VIII, VWF antigen, VWF activity, and VWF activity:VWF antigen ratio results are normal, then a computer-generated interpretive comment indicating no evidence of von Willebrand disease will be provided.
If VWF activity assay is less than 55% or VWF activity:VWF antigen ratio is abnormally increased, then VWF ristocetin cofactor activity assay will be performed at an additional charge.
If VWF antigen is less than 55%, the VWF activity is less than 55%, or the VWF activity:VWF antigen ratio is abnormally low, then VWF multimer analysis will be performed at an additional charge.
If any test results are abnormal, all results will be reviewed by a coagulation consultant and a von Willebrand Disease Interpretation will be provided at an additional charge.
For more information see von Willebrand Disease Profile.
Special Instructions
Method Name
AVWPI: Technical Interpretation
F8A, F8A, 8BETH: Optical Clot-Based
RIST: Ristocetin-Induced Agglutination
VWAG, VWACT: Latex Immunoassay (LIA)
VWFMP: Agarose Gel Electrophoresis/Infrared Dye-Labeled Antibody Detection
Reporting Name
von Willebrand Disease ProfSpecimen Type
Plasma Na CitSpecimen Minimum Volume
2 Plastic vials, each containing 1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Cit | Frozen | 14 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
2 to 12 daysTest Classification
See Individual Test IDsCPT Code Information
85240-Coagulation factor VIII assay
85246-von Willebrand factor antigen
85397-von Willebrand factor activity
85245-von Willebrand factor ristocetin cofactor activity (if appropriate)
85247-von Willebrand factor multimer (if appropriate)
85335-Bethesda titer (if appropriate)
85335-Coagulation factor VIII inhibitor screen (if appropriate)
85390-26-Special coagulation interpretation (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AVWPR | von Willebrand Disease Prof | 48593-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| F8A | Coag Factor VIII Activity Assay, P | 3209-4 |
| VWAG | von Willebrand Factor Ag, P | 27816-8 |
| AVWPI | von Willebrand Disease Tech Interp | 48595-3 |
| VWACT | von Willebrand Factor Activity, P | 68324-3 |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| F8IS | Coag Factor VIII Assay Inhib Scrn,P | No | No |
| AVWPQ | von Willebrand Disease Interp | No | No |
| VWFMP | von Willebrand Factor Multimer, P | Yes, (order VWFMS) | No |
| RIST | Ristocetin Cofactor, P | No | No |
| 8BETH | FVIII Bethesda Units, P | No | No |