CDOS

Lupus Anticoagulant Reflex

Test Code: 117892

Performing Lab: LabCorp

CPT Code: 85613 001 85732 001

Test Link (Copy)

Synonym

Lupus Anticoagulant; Lupus Anticoagulant Screen

Specimen Type

Plasma, FROZEN

Specimen Container

Blue-top (sodium citrate) tube

Volume

2 mL

Minimum Volume

1 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.[19] Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.[20,21] 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 unless the sample is collected using a winged blood collection device (butter- fly) collection system. With a winged blood collection set a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacuated tube.[22,23] 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.

Patient Prep

Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin (Coumadinr) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.

Unacceptable Conditions

Severe hemolysis; improper labeling; clotted specimen; specimen diluted with I.V. fluids; samples thawed in transit; improper sample type; sample out of stability

Temperature

FREEZE

Methodology

PTT-LA (lupus-sensitive aPTT) and DRVVT screen; mixing study if screening tests are prolonged; confirmation if the mixing studies do not correct.

Stability

Frozen: 28 days

Result Code	Result Name	LOINC
117003	PTT-LA	34571-0
117891	dRVVT	6303-2
117893	Lupus Reflex Interpretation	75514-0

Reflex Order Code	Reflex Order Name
117040	PTT-LA Mix
117020	Hexagonal Phase Phospholipid
117912	dRVVT Mix
117923	dRVVT Confirm

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