Lupus Anticoagulant With Reflex
Also known as: Lupus Anticoagulant, Lupus Anticoagulant Screen
Use
Qualitative detection of lupus anticoagulants in plasma6
Special Instructions
Avoid anticoagulant therapy prior to testing. Patients should ideally discontinue warfarin (Coumadin®) two weeks before testing and heparin, direct Xa, and thrombin inhibitor therapies about three days prior. Collect plasma using double centrifugation and refer to collection instructions for detailed guidance. Confirmatory and reflex testing may extend the turnaround time.
Limitations
Detection of LAC is prone to interferences inherent to phospholipid-based coagulation assays. Factors like elevated c-reactive protein and increased factor VIII can lead to false results. Use of certain drugs or conditions such as anticoagulation therapy complicates testing and entails interpretation caution. Vitamin K antagonists and different types of heparin can affect aPTT and dRVVT results. Direct Oral Anticoagulants cause variable effects on assays, potentially leading to both false-positive and false-negative interpretations. Adsorption techniques can mitigate DOAC interference. Testing should be repeated 12 weeks after initial positive findings to confirm persistence.
Methodology
Other
Biomarkers
LOINC Codes
- 75515-7
- 34571-0
- 6303-2
- 75514-0
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
1 mL
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. Mixed by gentle inversion at least six times before processing.
Patient Preparation
Avoid anticoagulant therapy; ideally, discontinue warfarin two weeks and heparin three days prior to testing.
Storage Instructions
Freeze immediately and maintain frozen until tested.
Causes for Rejection
Severe hemolysis, improper labeling, clotted specimens, samples thawed in transit.
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |