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HelpTest Code vWP von Willebrand Panel
Aliases
von Willebrand Disease Profile
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).
Patient Preparation
Patient should not be receiving anticoagulant treatment (eg, warfarin, heparin).
Patient should also not be receiving fibrinolytic agents (streptokinase, urokinase, tissue plasminogen activator: tPA).
If patient has been recently transfused, it is best to perform this study pretransfusion, if possible.
Special Collection Instructions
Specimen must be collected prior to factor replacement therapy.
Properly filled 9:1 ratio (blood to anticoagulant); 3.2% NaCitrate
Collection Method
Venous Draw
Container
Light-blue top (3.2% sodium citrate)
Preferred Specimen
2.7mL Lt. Blue (3.2% NaCitrate)
Acceptable Specimens
1.8 mL Lt. Blue (3.2% NaCitrate) tube
Reference or Target Ranges
Normal:
von Willebrand Factor Activity: 48.8 - 163.4%
von Willebrand Factor Antigen: 66.1 - 176.3%
Factor VIII: 50 - 150%
Reportable Units
% (percentage)
Reasons for Rejection
| Hemolysis Threshold | Visable unacceptable |
| Icterus Threshold | Visable unacceptable |
| Lipemia Threshold | Visable unacceptable |
| Interfering Subtances/Other |
Short draws, over draws, clotted, improperly labeled, or samples > 4 hours from collection |
Specimen Stability
| Ambient | Plasma – 4 hours |
| Refrigerated (4°C to 8°C) | N/A |
| Frozen(-70°C to -20°C) | 2 weeks@ -20°C; 1 year @ -70°C |
Performance Information
| Days and Time Performed | Batched daily Monday - Friday |
| Expected Turn Around Time | Batched Monday – Friday |
| Stat Availability | No |
| Performing Bench | Coagulation |
| Methodology/Method Description | Werfen ACL TOPS - Latex Immunoturbidimetric Assay |
Panel Components
von Willebrand Factor Activity
von Willebrand Factor Antigen
Factor VIII
Additional follow-up tests per guidelines
Pathologist Interpretation
CPT Codes
85245, 85246, 85240, 83590 26
Additional Information / Important Notes
Patients with any of these (Intermediate or high probability):
- Abnormal personal bleeding history or event
- Abnormal aPTT result
- Known first-degree relative with VWD
Recommendation: Proceed with VWD Profile order.
For all other patients: please complete the Bleeding Assessment Tool. Guidelines recommend proceeding with VWD profile testing only if the score is abnormal.