###1: Lupus Anticoagulant Phospholipid-Dependence Test (40 µg/mL Phospholipid), Whole Blood
###3: This test checks for lupus anticoagulant, an antiphospholipid antibody that can interfere with clotting tests in the laboratory. It does not necessarily mean that you have an antiphospholipid syndrome.
["###4: A positive result may be associated with an increased risk of blood clots, but it must be interpreted with symptoms, other laboratory results, and repeat testing."]
Key facts at a glance
- LOINC
- 61354-7
- Short code
- LPT 40 ug PHA Bld
- Synonyms
- LPT 40 ug PHA Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 12
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
###5: What the test measures
###6: Lupus anticoagulant is an immune substance directed against phospholipid-binding proteins. The laboratory evaluates whether the sample prolongs a phospholipid-dependent clotting reaction and whether that effect is corrected with confirmatory testing.
###7: How the test is performed
###8: A whole-blood sample is collected and processed according to the laboratory’s validated procedure. Because clotting assays are sensitive to sample handling, timing, and reagent conditions, the laboratory may use more than one testing method or a confirmation step.
###9: Understanding the result
###10: A result may be reported as negative, positive, or indeterminate. An indeterminate result can occur with inadequate sample handling or interfering anticoagulant treatment and may require repeat testing.
###11: Preparation and medications
###11: Tell your clinician and laboratory about anticoagulant or antiplatelet medicines, recent bleeding, pregnancy, autoimmune disease, and any recent blood-thinning procedures. Do not stop prescribed medication without medical advice.
Reference range
Adult: 4.5-12.0 μg/dLN/A
Take your thyroid medication after the blood draw if applicable. No fasting required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
###2: Lupus anticoagulant test
Frequently asked questions
###14: Does a positive result mean I have antiphospholipid syndrome?
###16: Why might the test need to be repeated?
###18: Can medicines affect the result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy