VON WILLEBRAND FACTOR (VWF) ANTIGEN, PLASMA

Test Code

LAB307

CPT Codes
85246 LoiNC: 27816-8

Preferred Specimen

Adult: One 3 mL blue top tube
Pediatric: One 1.8mL pediatric blue top tube

Minimum Volume

1mL plasma

Instructions

Tube must be filled to etched line to perform testing.
Samples must be centrifuged at 3000 rpm for 10 minutes or using a high-speed centrifuge. Platelet poor plasma should be separated into 1 ml aliquots. Samples should be frozen within one hour (best practice), however samples stable for 4 hours. Samples must remain frozen during transport. Any samples that are received thawed are not suitable for testing.

Transport Temperature

Frozen (two 1 mL plasma aliquots)

Specimen Stability

Ambient: 4 hours if cap has not been removed or punctured
Frozen: 6 months (-70C)

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Clotted, thawed, underfilled tube, or gross hemolysis

Methodology
Latex particle enhanced immunotubridimetric assay on ACL TOP

Setup Schedule

Monday-Friday

Reference Range

55-200%

Clinical Significance

Blood group O individuals may have lower VWF activity levels than other ABO groups. Normal group O individuals may have VWF activity levels as low as 40-50%.

Performing Laboratory
West Virginia University Hospital, Inc.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.