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Lupus Anticoagulant

Published: July 27, 2026Updated: August 25, 2026

The lupus anticoagulant is an autoantibody that interferes with phospholipid-dependent coagulation tests, often leading to prolonged clotting times. It is associated with an increased risk of thrombosis.

Quick summary

Lupus anticoagulant is an antibody that can cause increased blood clotting.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
ratio
Clinical utility
diagnostic
Result kind
semi_quantitative
FDA-cleared
Roche LA, Siemens LA, Stago LA, Viper LA
interpretation: {"text":"A ratio within the reference range (0–1.2) indicates that lupus anticoagulant is not detected.","label":"Normal"}; {"text":"A ratio above 1.2 suggests the possible presence of lupus anticoagulant, necessitating further diagnostic evaluation.","label":"Elevated"}

The lupus anticoagulant (LA) is a type of antiphospholipid antibody that paradoxically increases the risk of blood clots despite prolonging clotting tests in laboratory settings. It is commonly tested as part of the coagulation panel to assess the risk of thrombotic events.

LA testing involves multiple steps, including screening, mixing, and confirmation tests. A ratio above the reference range (0–1.2) indicates the possible presence of lupus anticoagulant, which may warrant further clinical evaluation.

Detection of LA is crucial for diagnosing antiphospholipid syndrome (APS), a condition that can lead to complications such as deep vein thrombosis, stroke, and recurrent miscarriages. Early identification can help in the management and prevention of these complications.

Frequently asked questions

What is the significance of a positive lupus anticoagulant test?
A positive test indicates an increased risk of blood clots, which can lead to conditions such as deep vein thrombosis, pulmonary embolism, or stroke.
Can lupus anticoagulant affect pregnancy?
Yes, it can increase the risk of complications such as recurrent miscarriages and preeclampsia.
  1. 1
    Lupus Anticoagulant TestingSource
  2. 2
    Antiphospholipid SyndromeSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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 25, 2026. · Read our editorial policy