Von Willebrand Factor Activity
General Information
- Lab Name
- VWF Activity
- Lab Code
- VWFACT
- Epic Name
- Von Willebrand Factor Activity
- Description
VWF activity is a turbidimetric latex bead-based assay that measures the binding of von Willebrand factor (VWF) to platelet receptor glycoprotein Ib (GPIb) without ristocetin.
The diagnosis or exclusion of any type of von Willebrand disease should never be based solely on the VWF activity result. This test should always be interpreted in conjunction with a group of tests (Factor VIII activity, VWF antigen, collagen binding activity and multimer analysis) in the context of the patient's medical history and clinical presentation. Von Willebrand activity can be used to monitor therapeutic efficacy of treatment with DDAVP (desmopressin) or von Willebrand factor concentrates in patients with von Willebrand disease.
- Synonyms
- Ristocetin Cofactor Alternative, VWF Activity, VWF GPIbM activity
- Components
Interpretation
- Method
Innovance VWF:GPIbM Latex-Immunoassay
- Reference Range
-
Units: %
Female Male Age Range Age Range 0- 50-200 0- 50-200 Effective date: 10/03/2006
- Interferences and Limitations
The presence of rheumatoid factor or human anti-mouse antibody (HAMA) may give a falsely elevated (observed more often) or depressed result.
This assay is not affected by unconjugated bilirubin up to 60 mg/dL, conjugated bilirubin up to 40 mg/dL, triglycerides up to 726 mg/dL and rheumatoid factor up to 438 IU/mL.
Ordering & Collection
- Specimen Type
- Blood
- Collection
-
3 or 5 mL BLUE TOP (CITRATE) tube
- Handling Instructions
The Laboratory MUST process specimen within 4 hrs of blood collection.
- Quantity
- Requested: Entire Sample
Processing
- Receiving Instructions
UW-MT Instructions: Take specimen to UW-MT Coag for processing. Coag tech will freeze plasma sample for transport to HMC Coag.
HMC Instructions: Take specimen to HMC Coag lab for processing.
Outside Laboratory: Centrifuge for 10 minutes, remove plasma & re-spin plasma for another 10 minutes. Decant & Freeze plasma (minimum 1.0 mL) @ -20°C to -80°C. Send frozen on dry ice.
- Misc Sendout
Performance
- Lab Department
- Coagulation(COAG)
- Frequency
- Run on Tuesday and Friday. Reported by end of day.
- Available STAT?
- Yes, with LMR approval
- Performing Location(s)
-
HMC Coagulation
206-520-4600325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420
Billing & Coding
- CPT Codes
- 85245
- LOINC
- 68324-3
- Interfaced Order Code
- UOW843
- Interfaced Result Code
- UOW843