Hexagonal Phase Phospholipid (HPP)
Also known as: Neutralization, Hexagonal Phase Phospholipid
Use
This test system is designed for the qualitative detection of lupus anticoagulants in plasma.6
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions. Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.
Limitations
Anticoagulant therapy may cause false-positive results. Plasma heparin levels >2 IU/mL may interfere with this test. Platelets are a rich source of phospholipid that can neutralize LA. Improper preparation of the platelet-poor plasma at collection reduces the sensitivity of this assay for LA. This test is subject to false-positive cross-reactivity with factor VIII inhibitors.
Methodology
Other
Biomarkers
LOINC Codes
- 3282-1
- 3282-1
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Citrated plasma samples should be collected by double centrifugation. Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples, except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used. 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 recentrifuge for 10 minutes. Use a second plastic pipette to remove the 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 No. 49482). Freeze immediately and maintain frozen until tested.
Patient Preparation
Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin (Coumadin®) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing.
Storage Instructions
Freeze.
Causes for Rejection
Severe hemolysis; improper labeling; clotted specimen; specimen diluted with IV fluids; samples thawed in transit; improper sample type; sample out of stability