From the Guidelines
Antiphospholipid syndrome (APS) is a thrombo-inflammatory disease driven by antiphospholipid antibodies (aPL) that induce thrombosis, pregnancy morbidity, and other autoimmune and inflammatory manifestations. 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. The clinical features of APS are not specific and can include deep vein thrombosis, pulmonary embolism, stroke, heart attack, and pregnancy complications such as recurrent miscarriages.
Key aspects of APS diagnosis and management include:
- Detection of antiphospholipid antibodies, including lupus anticoagulant, anticardiolipin, and anti-beta2 glycoprotein I antibodies
- Use of non–enzyme-linked immunosorbent assays (ELISAs) and semiquantitative reporting of titers
- Role of immunoglobulin (Ig) M and IgA isotypes in APS diagnosis
- New 2023 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria for APS, which set moderate and high titer thresholds at 40 Unit (U) and 80 U levels, respectively 1
The distinction between classification criteria and routine clinical care is crucial, as classification criteria aim to enhance specificity and improve research quality, while routine clinical care focuses on optimizing APS diagnosis and patient care 1. The goal of APS management is to prevent blood clots and improve pregnancy outcomes, typically through the use of anticoagulant medications such as warfarin, heparin, or direct oral anticoagulants, and low-dose aspirin and heparin injections in pregnant women. Accurate diagnosis and management of APS are essential to reduce morbidity, mortality, and improve quality of life for affected individuals.
From the Research
Definition and Characteristics of Antiphospholipid Syndrome
- Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies (aPLs) that predispose individuals to thrombotic events and pregnancy-related complications 2, 3.
- APS can occur as a primary condition or in association with other autoimmune diseases, most commonly systemic lupus erythematosus (SLE) 2, 3.
- The syndrome is marked by recurrent vascular thromboses and pregnancy complications, with other clinical features including thrombocytopenia, Coombs-positive hemolytic anemia, heart valve disease, renal microangiopathy, and neurologic disorders 4.
Clinical Manifestations and Diagnostic Criteria
- Clinical manifestations of APS include venous and arterial thrombosis, pregnancy morbidity, and neurological symptoms 2, 3.
- Diagnosis of APS requires both a clinical manifestation (arterial or venous thrombosis and/or pregnancy morbidity) and persistently positive aPL 3.
- The diagnostic criteria are based on clinical and laboratory findings, including the presence of lupus anticoagulant, anticardiolipin, and anti-beta-2-glycoprotein I antibodies 2, 4.
Treatment and Management Strategies
- Treatment for APS is based on the patient's clinical status, presence of an underlying autoimmune disease, and history of thrombotic events 3.
- Anticoagulation therapy, including warfarin and low-molecular-weight heparin, is the mainstay of treatment for APS 2, 5.
- Pregnancy complications are usually managed with low-dose aspirin in association with low molecular weight heparin 3.
- Refractory forms of APS may benefit from adding hydroxychloroquine and/or intravenous immunoglobulin to anticoagulation therapy 3.
Catastrophic Antiphospholipid Syndrome (CAPS)
- CAPS is a rare, severe variant of APS, marked by rapid-onset, widespread thrombosis leading to multi-organ failure 2, 4.
- CAPS is usually triggered by infections, surgical procedures, or cessation of anticoagulation therapy 2.
- Treatment of CAPS requires a combined therapeutic approach, including anticoagulation, glucocorticoids, plasma exchange, and/or intravenous immunoglobulin 2, 4.