Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
The quantitation of Von Willebrand Factor Antigen is required for the typing of von Willebrand disease. Type 2 vWD have a much lower antigen compared to function and this has implications for treatment and monitoring
Specimen container paediatric:
Light blue – sodium citrate
Specimen container adult:
Light blue – sodium citrate
Minimum volume paediatric:
2.6mL
Minimum volume adult:
5.4mL
Special requirements:
Tube must be correctly filled to line, to ensure correct ratio of blood to anticoagulant, ensure adequate mixing.
Sample stability:
4 hrs
Transport requirements:
Samples should be transported to lab without delay
Availability:
All testing performed at RVI Haematology laboratory and available during routine hours, Monday to Friday. Testing is usually performed on a weekly basis, depending on batch size availability.
Freq analysis:
Continuous
Add on test:
[email protected] (external)
Quality assurance:
UK NEQAS Blood Coagulation
Reference ranges:
40 to 150 IU/dL
Note: For Haemostatic tests, paediatric reference ranges may be different to adult ranges.
Other info:
Plasma von Willebrand factor concentration.Performed as part of a vW Screen.