Tests and diagnosis
By Mayo Clinic staffIf you have one or more episodes of thrombosis or pregnancy loss that are not explained by known health conditions, your doctor can schedule blood tests to check for abnormal clotting and for the presence of antibodies to phospholipid-binding proteins.
Blood tests for antiphospholipid syndrome look for at least one of the following three antibodies in your blood:
- Lupus anticoagulant
- Anti-cardiolipin
- Beta-2 glycoprotein I (B2GPI)
To confirm a diagnosis of antiphospholipid syndrome, the antibodies must appear in your blood at least twice, in tests conducted at least 12 weeks apart.
- Donadini MP, et al. Antiphospholipid syndrome: A challenging hypercoagulable state with systemic manifestations. Hematology/Oncology Clinics of North America. 2010;24:669.
- Erkan D, et al. Antiphospholipid syndrome. In: Firestein GS, et al. Kelley's Textbook of Rheumatology. 8th ed. Philadelphia, Pa.: Saunders Elsevier; 2008. http://www.mdconsult.com/das/book/body/208746819-6/0/1807/0.html. Accessed Feb. 22, 2011.
- Bermas BL, et al. Pathogenesis of the antiphospholipid syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 22, 2011.
- Bermas BL, et al. Treatment of the antiphospholipid syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 22, 2011.
- Blood thinner pills: Your guide to using them safely. U.S. Department of Health and Human Services: Agency for Healthcare Research and Quality. http://www.ahrq.gov/consumer/btpills.htm. Accessed Feb. 22, 2011.
- Long BR, et al. The role of antiphospholipid syndrome in cardiovascular disease. Hematology/Oncology Clinics of North America. 2008;22:79.
- Bermas BL, et al. Clinical manifestations of the antiphospholipid syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 22, 2011.
- Antiphospholipid syndrome information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/antiphosphlipid/antiphospholipid.htm. Accessed Feb. 22, 2011.
- Vitamin K. The National Academies Press. http://books.nap.edu/openbook.php?record_id=10026&page=162. Accessed Feb. 28, 2011.
- Pruthi RK (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 27, 2011.
- Giannakopoulos B, et al. How we diagnose the antiphospholipid syndrome. Blood. 2009;113:985.


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