Antiphospholipid Syndrome: Diagnosis and Management
- Garcia D, Erkan D.
- Diagnosis and Management of the Antiphospholipid Syndrome. N Engl J Med 2018;May 23:[Epub ahead of print].
The following are key points to remember from this review article about the diagnosis and management of antiphospholipid syndrome (APS):
- APS is a systemic autoimmune disease defined by thrombotic or obstetrical events that occur in patients with persistent antiphospholipid antibodies.
- Antiphospholipid antibodies target β2-glycoprotein I. This suppresses the activity of tissue factor pathway inhibitor, reduces activated protein C activity, and activates complement.
- Thrombotic events in APS can be venous, arterial, or microvascular. Patients with catastrophic APS present with thrombosis involving multiple organs.
- Obstetrical APS is characterized by fetal loss after the 10th week of gestation, recurrent early miscarriages, intrauterine growth restriction, or severe preeclampsia.
- APS is often associated with other systemic autoimmune diseases (such as systemic lupus erythematosus); however, APS commonly occurs without other autoimmune manifestations.
- Not every positive antiphospholipid antibody test is clinically significant. Lupus anticoagulant testing correlates better with clinical events than anti-cardiolipin antibodies or anti-β2-glycoprotein I antibodies.
- The risk of thrombosis in a patient with antiphospholipid-antibody-positive testing but no prior thrombotic episodes or other risk factors (e.g., autoimmune disease) is <1% per year.
- Persistently positive APS requires that laboratory tests be conducted at least 12 weeks apart. A high-risk profile involves a persistently positive lupus anticoagulant independent of anti-cardiolipin or anti-β2-glycoprotein I antibody results.
- The use of low-dose aspirin for “primary thrombosis prevention” in patients with APS but no prior thrombosis is controversial. No other prophylactic therapy has been robustly proven effective.
- For patients with APS and a history of venous thrombosis, treatment with heparin and warfarin (target international normalized ratio [INR] 2-3) is recommended. Anticoagulation is usually recommended indefinitely for patients whose venous thrombosis was unprovoked.
- Antiphospholipid antibodies can lead to falsely elevated INR results (most common with point-of-care devices). Confirming the factor X activity (using a chromogenic assay) can be useful to calibrate the target INR range.
- Currently, there is insufficient evidence to support the use of direct oral anticoagulants in APS patients.
- Many experts recommend warfarin use for patients with APS and a history of arterial thromboses. However, patients with a history of stroke and a low-titer of anticardiolipin antibodies may be treated with aspirin alone.
- Early treatment is essential in catastrophic APS. This usually involves anticoagulants, steroids, intravenous immune globulin, and plasma exchange.
- Low-dose aspirin and therapeutic-dose heparin should be used in pregnant women with thrombotic APS, regardless of the pregnancy history. Low-dose aspirin or prophylactic-dose heparin can be used in pregnant women with APS, but no prior history of thrombosis (including 6 weeks postpartum).
Keywords: Antibodies, Anticardiolipin, Antibodies, Antiphospholipid, Antiphospholipid Syndrome, Anticoagulants, Aspirin, Cardiolipins, Factor X, Fetal Growth Retardation, Heparin, Immunoglobulins, Intravenous, Lupus Coagulation Inhibitor, Lupus Erythematosus, Systemic, Point-of-Care Systems, Postpartum Period, Pre-Eclampsia, Pregnancy, Protein C, Primary Prevention, Risk Factors, Stroke, Thromboplastin, Thrombosis, Thromboembolism, Venous Thrombosis, Vascular Diseases, Warfarin
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