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Lupus Anticoagulant Testing

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Also known as: LA; Lupus Anticoagulant Panel; Lupus Inhibitor; LA Sensitive PTT; PTT-LA; Dilute Russell Viper Venom Test; DRVVT; Modified Russell Viper Venom Test; MRVVT
Formal name: Lupus Anticoagulant
Related tests: Antiphospholipid Antibodies; Hexagonal Phase Phospholipid Neutralization Assay; PTT; Thrombin Time; Cardiolipin Antibodies; PT and INR; Beta-2 Glycoprotein 1 Antibodies; Kaolin Clotting Time; Platelet Neutralization Test; Factor V Leiden Mutation and PT 20210 Mutation; Homocysteine; Protein C and Protein S; Antithrombin

At a Glance

Why Get Tested?

To help investigate the cause of a blood clot (thrombotic episode); to evaluate a prolonged partial thromboplastin time (PTT); to help determine the cause of recurrent miscarriages, or as part of an evaluation for antiphospholipid syndrome; the tests are not used to diagnose the chronic autoimmune disorder systemic lupus erythematosus (SLE), commonly known as lupus.

When to Get Tested?

When you have had signs and symptoms of a blood clot in a vein or artery (known as thrombosis or thromboembolism); when you have a prolonged PTT test; when you have had recurrent miscarriages

Sample Required?

A blood sample obtained by inserting a needle into a vein in your arm

Test Preparation Needed?

None

The Test Sample

What is being tested?

Lupus anticoagulants (LA) are autoantibodies produced by the immune system that mistakenly attack certain components of the body's own cells. They specifically target phospholipids as well as the proteins associated with phospholipids that are found in the outer-most layer of cells (cell membranes). These autoantibodies interfere with the blood clotting process in a way that is not fully understood and increase a person's risk of developing a blood clot. Lupus anticoagulant testing is a series of tests that detect the presence of LA in the blood.

The lupus anticoagulant test's name may seem odd or confusing for two reasons:

  • Lupus anticoagulants were so-named because they were first found among patients with lupus, but LA testing is not used to diagnose the autoimmune disorder and LA are frequently absent in people with lupus. LA may also occur in individuals with other conditions and in people who take certain medications. The antibodies are present in about 2-4% of the general population and may develop in people with no known risk factors.
  • The term "anticoagulant" is part of the name because LA actually reduce clotting in laboratory tests that are used to evaluate coagulation. For example, they inhibit the chemical reactions that lead to clotting in the partial thromboplastin time (PTT), a test routinely used to evaluate clotting. However, the presence of LA in the human body is associated with an increased risk of developing inappropriate blood clots. Importantly, lupus anticoagulant itself does not cause bleeding in the body.

There is no single test for the detection of lupus anticoagulant and it cannot be measured directly. The presence of LA is usually determined by using a panel of sequential tests for which there is no standardization.

  • Initial testing typically involves one or more tests that depend on phospholipid reagents, usually PTT, the LA-sensitive PTT (PTT-LA) or dilute Russell viper venom test (DRVVT). All of these tests measure the time it takes (in seconds) for a sample to clot; LA prolongs that time.
  • Depending on the results of these initial tests, certain follow-up tests are performed to either confirm or exclude the presence of lupus anticoagulant. For more on this, see the section titled "How is it used?".

LA may increase the risk of developing blood clots in both the veins and arteries, often in the veins in the legs (deep vein thrombosis, DVT). These clots may block blood flow in any part of the body, leading to stroke, heart attack, or pulmonary embolism. LA is also associated with recurrent miscarriages. It has been suggested that LA causes clots to form that block blood vessels of the placenta, affecting growth of the developing baby, and that LA may also directly attack the tissue of the placenta, affecting its development.

The lupus anticoagulant is one of three primary antiphospholipid antibodies that are associated with an increased risk of thrombosis and antiphospholipid antibody syndrome (APS), an autoimmune disorder characterized by excess blood clot formation and pregnancy complications. The other two are cardiolipin antibodies and beta-2 glycoprotein 1 antibody. Individually and together, they increase a person's tendency to clot inappropriately. People with APS are at greater risk for clotting if they test positive for all three antibodies. However, thrombosis appears more common in people with LA.

Not everyone with antiphospholipid antibodies will develop symptoms. Antiphospholipid antibodies are present in about 5% of healthy individuals.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

(2013 January 8). King, G.G.T., et al. Partial Thromboplastin Time - Lupus Anticoagulant Screen. Medscape. Available online at http://emedicine.medscape.com/article/2084887-overview#a30 through http://emedicine.medscape.com. Accessed May 2014.

(Updated 2013 January 22). Gersten, T. Lupus anticoagulants. MedlinePlus. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000547.htm through http://www.nlm.nih.gov. Accessed May 2014.

(2012 May 17). What Is Antiphospholipid Antibody Syndrome? NIH National Heart Lung and Blood Institute. Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/aps/ through http://www.nhlbi.nih.gov. Accessed May 2014.

Mayo Clinic Staff. (Updated 2014 April 15). Antiphospholipid Syndrome. Mayo Clinic. Available online at http://www.mayoclinic.org/diseases-conditions/antiphospholipid-syndrome/basics/definition/con-20028805 through http://www.mayoclinic.org. Accessed May 2014.

Pagana, K. D. & Pagana, T. J. (© 2014). Mosby's Manual of Diagnostic and Laboratory Tests Reference 5th Edition: Mosby, Inc., Saint Louis, MO. Pp 68-69.

(Updated 2014 January). Antiphospholipid Syndrome – APS. Arup Laboratories. Available online at http://www.arupconsult.com/Topics/APS.html?client_ID=LTD through http://www.arupconsult.com. Accessed May 2014.

(Updated 2014 February 19). Schick, P. et al. Hypercoagulability - Hereditary Thrombophilia and Lupus Anticoagulants Associated With Venous Thrombosis and Emboli Workup. Medscape. Available online at http://emedicine.medscape.com/article/211039-workup through http://emedicine.medscape.com. Accessed May 2014.

(2013 January 7). Berg, T. et al. Antiphospholipid Syndrome and Pregnancy. Medscape. Available online at http://emedicine.medscape.com/article/261691-overview through http://emedicine.medscape.com. Accessed May 2014.

(2012 April 6). Thrombocytopenia (low platelet count). Mayo Clinic. Available online at http://www.mayoclinic.org/diseases-conditions/thrombocytopenia/basics/causes/con-20027170 through http://www.mayoclinic.org. Accessed May 2014.

(Updated 2013 September 1). Vyas, J. VDLR Test. MedlinePlus. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003515.htm through http://www.nlm.nih.gov. Accessed May 2014.

Clark, C. et al. The lupus anticoagulant: results from 2257 patients attending a high-risk pregnancy clinic. Blood 2013; 122(3): 341-347.

(Updated 2013 July 30). Bick, R. et al. Miscarriages Caused by Blood Coagulation Protein or Platelet Deficits Clinical Presentation. Medscape. Available online at http://emedicine.medscape.com/article/210857-clinical#a0218 through http://emedicine.medscape.com. Accessed May 2014.

(2012 January 19). Belilos et al. Antiphospholipid syndrome. Medscape. Available online at http://emedicine.medscape.com/article/333221-overview through http://emedicine.medscape.com. Accessed May 2014.

(Updated March 13, 2013) Meroni, P. American College of Rheumatology. Antiphospholipid Syndrome. Available online at http://www.rheumatology.org/Practice/Clinical/Patients/Diseases_And_Conditions/Antiphospholipid_Syndrome/ through http://www.rheumatology.org. Accessed June 2014.

Wintrobe's Clinical Hematology. 12th ed. Greer J, Foerster J, Rodgers G, Paraskevas F, Glader B, Arber D, Means R, eds. Philadelphia, PA: Lippincott Williams & Wilkins: 2009, Pp 1447-1453.

Sources Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

Castellone, D. (2001 January 8). The Lupus Anticoagulant: Truth or Consequence. Advance Newsmagazines [On-line Newsletter]. Available online at http://www.advanceforal.com/common/editorial/editorial.aspx?CC=4712 through http://www.advanceforal.com.

(2002 November 19, Updated). Antiphospholipid Antibody. Mass Gen. Hospital Pathology Service Laboratory Medicine [On-line information]. Available online at http://www.mgh.harvard.edu/labmed/lab/coag/handbook/co003100.htm#co003100 through http://www.mgh.harvard.edu.

(2002 October 24). Anti-Phospholipid Antibody. The Doctor's Doctor [On-line information]. Available online at http://www.thedoctorsdoctor.com/diseases/antiphospholipid_antibody.htm through http://www.thedoctorsdoctor.com.

Assay for Lupus Anticoagulants [On-line information]. Available online at http://www.medinfo.ufl.edu/year2/coag/lupus.html through http://www.medinfo.ufl.edu.

Lupus Anticoagulant Profile. University of Alabama at Birmingham [On-line information]. Available online at http://peir.path.uab.edu/coag/article_3.shtml through http://peir.path.uab.edu.

(2001 January 10, Modified). Lupus Anticoagulant Panel. Duke University Regional Referral Laboratory Services, Clinical Coagulation Laboratory [On-line Test Panel]. Available online at http://pathology.mc.duke.edu/coag/Panel.htm through http://pathology.mc.duke.edu.

Duke University Medical Center Clinical Coagulation Laboratory Coagulation Test Descriptions [On-line information]. Available online at http://pathology.mc.duke.edu/coag/TestDes.htm through http://pathology.mc.duke.edu.

Elstrom, R. (2001 October 17, Updated). Lupus Anticoagulants. MEDLINEplus Health Information, Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000547.htm.

University of Illinois - Urbana/Champaign Carle Cancer Center, Hematology Resource Page, Patient Resources, Antiphospholipid Antibody Syndrome. Available online at http://www.admin.med.uiuc.edu/hematology/PtAPS.htm through http://www-admin.med.uiuc.edu.

Coagulation Test Panels. Clinical and Research Laboratories, Florida Hospital Cancer Institute [On-line information]. Available online at http://www.fhci-labs.com/researchlabs/clinicallabs/hemostasisandthrombosis/panels.htm through http://www.fhci-labs.com.

Laposata, M. & Vancott, E. (2000 January). How to work up hypercoaguability. CAP In the News [On-line Coagulation Case Study]. Available online at http://www.cap.org/CAPToday/casestudy/coag5.html through http://www.cap.org.

Bleeding Disorders. The Merck Manual of Medical Information-Home Edition, Section 14. Blood Disorders, Chapter 155 [On-line information]. Available online at http://www.merck.com/mrkshared/mmanual_home/sec14/155.jsp through http://www.merck.com.

Menta, S. (1999 Spring). The Coagulation Cascade. Physiology Disorders Evaluation, College of Medicine, Univ of Florida [On-line information]. Available online at http://www.medinfo.ufl.edu/year2/coag/title.html through http://www.medinfo.ufl.edu.

Elstrom, R. (2001 November 25, Updated). PTT. MEDLINEplus Health Information, Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003653.htm.

Kovacs, B. (2001 November 26, Updated). Systemic lupus Erythematosus. MEDLINEplus Health Information, Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000435.htm.

DeLoughery, T. (1999 March 15). Tests of Hemostasis and Thrombosis. OHSU [Online student handout]. Available online at http://www.ohsu.edu/som-hemonc/handouts/deloughery/printtest.html through http://www.ohsu.edu.

Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO.

(2006 September). Lupus Anticoagulant Panel. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Hematologic_Disease/Lupus_Anticoagulant_Panel.html through http://www.arupconsult.com. Accessed on 3/25/07.

(© 2007). Lupus Anticoagulant Panel with Reflex to 1:1 Mixes & Confirmations. ARUP's Laboratory Test Directory [On-line information]. Available online at http://www.aruplab.com/guides/ug/tests/0030181.jsp through http://www.aruplab.com. Accessed on 3/25/07.

(2006 August 1 Reviewed). Antiphospholipid Syndrome. MedicineNet.com [On-line information]. Available online at http://www.medicinenet.com/antiphospholipid_syndrome/article.htm through http://www.medicinenet.com. Accessed on 3/31/07.

(© 2007). Antiphospholipid Antibodies. CAP [On-line information]. Available online through http://www.cap.org. Accessed on 3/25/07.

Salmon, J. et. al. (2007 March 2). The Antiphospholipid Syndrome as a Disorder Initiated by Inflammation: Implications for the Therapy of Pregnant Patients CME. Medscape from Nat Clin Pract Rheumatol 3(3):140-147 [On-line information]. Available online at http://www.medscape.com/viewarticle/553035 through http://www.medscape.com. Accessed on 3/25/07.

(© 2010). Antiphospholipid Antibodies. Lupus Foundation of America [On-line information]. Available online at http://www.lupus.org/webmodules/webarticlesnet/templates/new_aboutaffects.aspx?articleid=82&zoneid=17 through http://www.lupus.org. Accessed August 2010.

Belilos, E. and Carsons, S. (Updated 2009 August 3). Antiphospholipid Syndrome. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/333221-overview through http://emedicine.medscape.com. Accessed August 2010.

Berg, T. (2009 December 1). Antiphospholipid Antibody Syndrome and Pregnancy. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/261691-overview through http://emedicine.medscape.com. Accessed August 2010.

Gersten, T. (Updated 2009 January 1). Lupus anticoagulants. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000547.htm. Accessed August 2010.

Rodgers, III, G. et. al. (Updated 2010 August). Antiphospholipid Syndrome – APS. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/APS.html?client_ID=LTD through http://www.arupconsult.com. Accessed August 2010.

Mayo Clinic Staff (2009 April 4). Antiphospholipid syndrome. MayoClinic.com [On-line information]. Available online at http://www.mayoclinic.com/health/antiphospholipid-syndrome/DS00921 through http://www.mayoclinic.com. Accessed August 2010.

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 70-71.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 692-693.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 774-775.

The Fritsma Factor: Summary of ISTH SSC 2009 Updated Guidelines for Lupus Anticoagulant Detection (October 2009). Available online at http://www.fritsmafactor.com/newfritsmafactor/?p=1947 through http://www.fritsmafactor.com. Accessed November 2010.

Devreese K, Hoylaerts M. Challenges in the Diagnosis of the Antiphospholipid Syndrome. Clinical Chemistry 56: 930-940, 2010. Available at http://www.clinchem.org/cgi/content/full/56/6/930 through http://www.clinchem.org. Accessed November 2010.

Pengo V, et.al Update of the guidelines for lupus anticoagulant detection. Journal of Thrombosis and Hemostasis, Vol. 7, issue 10 Pp. 1737-1740, October 2009. Available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1538-7836.2009.03555.x/full through http://onlinelibrary.wiley.com. Accessed November 2010.

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