From the Guidelines
Antiphospholipid antibody syndrome (APS) is a thrombo-inflammatory disease driven by antiphospholipid antibodies (aPL) that can induce thrombosis, pregnancy morbidity, and other autoimmune and inflammatory manifestations. This condition is characterized by the presence of antibodies that mistakenly attack phospholipids, leading to abnormal blood clotting in arteries and veins. According to the most recent guidance from the ISTH-SSC subcommittee on lupus anticoagulant/antiphospholipid antibodies 1, APS diagnosis is dependent on accurate detection and interpretation of aPL, including lupus anticoagulant, anticardiolipin antibodies, or anti-beta2-glycoprotein I antibodies.
Key Features of APS
- Thrombotic events, such as recurrent blood clots, stroke, and pregnancy complications like miscarriage and preeclampsia
- Presence of persistent antiphospholipid antibodies, including lupus anticoagulant, anticardiolipin antibodies, or anti-beta2-glycoprotein I antibodies
- Can occur on its own (primary APS) or alongside other autoimmune conditions like lupus (secondary APS)
Diagnosis and Treatment
- Diagnosis requires both clinical criteria (thrombotic events or pregnancy complications) and laboratory evidence of persistent antiphospholipid antibodies
- Treatment typically involves anticoagulation therapy with medications like warfarin, heparin, or direct oral anticoagulants to prevent future clots
- For pregnant women with APS, a combination of low-dose aspirin and low-molecular-weight heparin is often prescribed to improve pregnancy outcomes, as suggested by the 2023 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria for APS 1
Management and Monitoring
- Regular monitoring and adherence to prescribed anticoagulation therapy are essential for managing this chronic condition effectively
- The exact cause of APS remains unknown, but it likely involves a combination of genetic predisposition and environmental triggers that lead to the immune system producing these harmful antibodies, as noted in the updated guidance from the ISTH-SSC subcommittee on lupus anticoagulant/antiphospholipid antibodies 1
From the Research
Definition and Characteristics of Antiphospholipid Antibody Syndrome (APS)
- Antiphospholipid antibody syndrome (APS) is an autoimmune acquired thrombophilia characterized by recurrent thrombosis and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL) 2.
- APS can be primary, if it occurs in the absence of any underlying disease, or secondary, if it is associated with another autoimmune disorder, most commonly systemic lupus erythematosus 2, 3.
- The exact pathogenetic mechanism of APS is unknown, but different models have been proposed to explain how anti-PL autoantibodies might lead to thrombosis and pregnancy morbidity 2, 4.
Clinical Manifestations and Diagnosis
- Diagnosis of APS requires that a patient has both a clinical manifestation (arterial or venous thrombosis and/or pregnancy morbidity) and persistently positive aPL 2, 5.
- The clinical spectrum of the disease encompasses additional manifestations which may affect every organ and cannot be explained exclusively by a prothrombotic state 2.
- APS is associated with a wide spectrum of clinical manifestations, including thrombocytopenia, Coombs-positive haemolytic anaemia, heart valve disease, renal microangiopathy, and neurologic disorders 3, 5.
Treatment and Management
- Treatment for aPL-positive patients is based on the patient's clinical status, presence of an underlying autoimmune disease, and history of thrombotic events 2.
- Anticoagulation therapy is the mainstay of treatment for thrombotic APS, and indefinite anticoagulation is often required 2, 4.
- Pregnancy complications are usually managed with low-dose aspirin in association with low molecular weight heparin 2.
- Refractory forms of APS could benefit from adding hydroxychloroquine and/or intravenous immunoglobulin to anticoagulation therapy 2, 6.
- Promising novel treatments include anti-B cell monoclonal antibodies, new-generation anticoagulants, and complement cascade inhibitors 2, 4.