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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, warfarin).
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation:
1. Patient should not be receiving anticoagulant treatment (eg, warfarin, heparin). If not possible for medical reasons, note on request.
a. If medically feasible, for 4 to 6 hours before specimen collection, do not administer intravenous heparin.
b. If medically feasible, for 10 to 14 days before specimen collection, do not administer subcutaneous heparin or warfarin.
2. Patient should not be receiving fibrinolytic agents (streptokinase, urokinase, tissue plasminogen activator [tPA]).
3. It is recommended that specimens be collected pretransfusion. If patient has been transfused, a specimen should not be collected for 48 hours.
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vials
Specimen Volume: 3 mL Platelet-poor plasma 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. Immediately freeze plasma (no longer than 4 hours after collection) at -20° C or, ideally, -40° C or below.
Forms
1. Coagulation Patient Information (T675)
2. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Secondary ID
603550Useful 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 the VWF activity assay is less than 55% or the VWF activity:VWF antigen ratio is abnormally increased, then the VWF ristocetin cofactor activity assay will be performed at an additional charge.
If the 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 an interpretation will be provided at an additional charge.
For more information see von Willebrand Disease Profile.
Special Instructions
Method Name
AVWPI: Technical Interpretation
AVWPQ: Medical interpretation
F8A, F8A, 8BETH, F8IS: Optical Clot-Based
RIST: Ristocetin-Induced Agglutination
VWAG, VWACT: Latex Immunoassay (LIA)
VWFMP: Agarose Gel Electrophoresis
Reporting Name
von Willebrand Disease ProfSpecimen Type
Plasma Na CitSpecimen Minimum Volume
Platelet-poor plasma: 2 Plastic vials, each containing 1 mL platelet-poor plasma
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| 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.
COAGULATION FACTOR VIII ACTIVITY
Adults: 55-200%
Normal, full-term infants or healthy premature infants typically have levels greater than or equal to 40%.*
*See Pediatric Hemostasis References in Coagulation Guidelines for Specimen Handling and Processing.
VON WILLIEBRAND FACTOR ANTIGEN
55-200%
Note: Individuals of blood group "O" may have lower plasma von Willebrand factor (VWF) antigen than those of other ABO blood groups, such that apparently normal individuals of blood group "O" may have plasma VWF antigen as low as 40% to 50%, whereas the lower limit of the reference range for individuals of other blood groups may be 60% to 70%.
Children: Neonates, infants, and children have normal or mildly increased plasma VWF antigen, with respect to the adult reference range.
VON WILLEBRAND FACTOR ACTIVITY
55-200%
Normal, full-term infants may have mildly increased levels which reach adult levels by 90 days postnatal. Healthy, premature infants (30-36 weeks gestation) may have increased levels that reach adult levels by 180 days.
Note: Individuals of blood group "O" may have lower plasma von Willebrand factor (VWF) activity than those of other ABO blood groups, such that apparently normal individuals of blood group "O" may have plasma VWF activity as low as 40% to 50%, whereas the lower limit of the reference range for individuals of other blood groups may be 60% to 70%.
COAGULATION FACTOR VIII INHIBITOR SCREEN
Negative
RISTOCETIN COFACTOR
Adults: 55-200%
Note: Individuals of blood group "O" may have lower plasma von Willebrand factor (VWF) ristocetin cofactor activity than those of other ABO blood groups, such that apparently normal individuals of blood group "O" may have plasma VWF ristocetin cofactor activity as low as 40% to 50% whereas the lower limit of the reference range for individuals of other blood groups may be 60% to 70%.
Normal, full-term infants or healthy premature infants usually have levels in the adult range.
FACTOR VIII BETHESDA UNITS
≤0.5 Bethesda Units
Day(s) Performed
Monday through Friday
Report Available
2 to 12 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
See Individual Test IDsCPT Code Information
85240-Coagulation factor VIII assay
85246-von Willebrand factor antigen
85397-von Willebrand factor activity
85390-Technical interpretation
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 |