CDOS

von Willebrand Factor (vWF) Profile

Test Code: 084715

Performing Lab: LabCorp

CPT Code: 85245 001 85240 001 85246 001

Test Link (Copy)

Specimen Type

Plasma (platelet poor), FROZEN

Specimen Container

Blue-top (sodium citrate) tube

Volume

2 mL

Specimen Handling

CITRATED PLASMA SAMPLES SHOULD BE COLLECTED BY DOUBLE CENTRIFUGATION. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.[1] Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.[2,3] The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anti- coagulant with the blood. A discard tube is not required prior to collection of coagulation samples except when using a winged blood collection device (i.e. 'butterfly'), in which case a discard tube should be used.[4,5] When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue- top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and recentifuge for 10 minutes. Use a second plastic pipette to remove plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a LabCorp PP transpak frozen purple tube with screw cap (LabCorp 49482). FREEZE immediately and maintain frozen until tested. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.

Patient Prep

As VWF and FVIII are acute-phase reactant proteins, patients should be at ease when blood is drawn. Undue stress, such as a crying child or very recent exercise may elevate VWF levels, and these conditions should be avoided. Certain anticoagulant therapies, such as heparin, direct thrombin inhibitors, and direct Xa inhibitors may interfere with FVIII activity results but will not interfere with analysis of VWF. Do not draw from an arm with a heparin lock or heparinized catheter.

Unacceptable Conditions

Gross hemolysis; clotted specimen; frozen specimen thawed in transit; improper labeling; improper collection tube

Temperature

FREEZE

Methodology

See individual tests.

Result Code	Result Name	LOINC
086264	Factor VIII Activity	3209-4
086280	vWF Antigen	27816-8
164509	vWF Activity	107372-5
164509	vWF Activity	107372-5
164509	vWF Activity	107372-5

Reflex Order Code	Reflex Order Name
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report
910377	Coag Studies Interp Report

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