Antiphospholipid syndrome
Thrombosis or pregnancy morbidity with persistent antiphospholipid antibodies. Who to test, how anticoagulants wreck the lupus anticoagulant assay, why warfarin beats DOACs in high-risk APS, the obstetric regimen, catastrophic APS, and the non-criteria features (livedo, valve disease, thrombocytopenia) examiners use.
Tier 2Condition
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Antiphospholipid syndrome (APS) is an acquired autoimmune thrombophilia: venous, arterial or microvascular thrombosis, or pregnancy morbidity, with persistent antiphospholipid antibodies (aPL).
- Primary APS occurs alone. About a third of people with SLE carry aPL; around 10 to 15% of those with SLE develop APS. See SLE.
- Three tests: lupus anticoagulant (LA), anticardiolipin (aCL) and anti-beta2-glycoprotein I (anti-β2GPI). Positives must persist 12 weeks or more apart.
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Sources
- Therapeutic Guidelines: Rheumatology and Haematology (antiphospholipid syndrome)AU/NZTherapeutic Guidelines Limited (eTG complete), current online version, accessed November 2026
- Tektonidou MG et al. EULAR recommendations for the management of antiphospholipid syndrome in adults. Ann Rheum Dis 2019;78:1296-1304EULAR, 2019 (current EULAR version as of November 2026)
- Barbhaiya M et al. The 2023 ACR/EULAR antiphospholipid syndrome classification criteria. Arthritis Rheumatol 2023;75:1687-1702ACR and EULAR, 2023
- Arachchillage DJ et al. Guidelines on the investigation and management of antiphospholipid syndrome. Br J Haematol 2024;205:855-80British Society for Haematology, 2024
- Devreese KMJ et al. An update on laboratory detection and interpretation of antiphospholipid antibodies for diagnosis of antiphospholipid syndrome: guidance from the ISTH-SSC Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibodies. J Thromb Haemost 2025;23:731-44International Society on Thrombosis and Haemostasis, 2025
- Pengo V et al. Rivaroxaban vs warfarin in high-risk patients with antiphospholipid syndrome (TRAPS). Blood 2018;132:1365-71Blood, 2018
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Turnstile bot check on sign-in and signed-out feedback