From the Guidelines
Elevated anticardiolipin antibodies are a significant risk factor for thrombosis and require further evaluation and potential treatment to prevent morbidity and mortality. The presence of these antibodies, particularly at high titers, is associated with an increased risk of stroke, deep vein thrombosis, and pulmonary embolism 1. According to the 2024 guideline for the primary prevention of stroke, a high-risk antiphospholipid (aPL) profile is defined as the presence of lupus anticoagulant or double or triple aPL positivity, including anticardiolipin antibodies, on two or more occasions at least 12 weeks apart 1.
Key Considerations
- Elevated anticardiolipin antibodies should be confirmed with repeat testing in 12 weeks to rule out transient elevations due to infections.
- Additional testing for lupus anticoagulant and anti-beta2 glycoprotein I antibodies is recommended to complete the antiphospholipid antibody panel.
- Patients with a history of blood clots or pregnancy complications and persistent positive antibodies should be considered for anticoagulation therapy.
- For those with thrombosis, warfarin with an INR target of 2-3 is standard, though direct oral anticoagulants may be considered in certain cases 1.
- Pregnant women with antiphospholipid syndrome (APS) may benefit from low-dose aspirin and prophylactic heparin.
Management and Treatment
- Regular follow-up with a rheumatologist or hematologist is essential for ongoing management.
- Patients without prior clots but with persistent antibodies may benefit from low-dose aspirin for primary prevention.
- The use of direct oral anticoagulants has been suggested in patients not able to achieve a target international normalized ratio despite good adherence to vitamin K antagonists (VKAs) or in those with contraindications to VKAs 1.
Evidence and Recommendations
- A recent meta-analysis demonstrated that patients with thrombotic APS randomized to direct oral anticoagulants compared with VKAs had increased odds of arterial thrombosis, especially stroke 1.
- The 2024 guideline for the primary prevention of stroke recommends anticoagulation therapy for patients with APS and a history of thrombosis 1.
- The clinical significance of anticardiolipin antibodies requires further investigation, particularly in the absence of systemic lupus erythematosus (SLE) 1.
From the Research
Significance of Elevated Anticardiolipin (aCL) Antibodies
Elevated anticardiolipin (aCL) antibodies have been associated with an increased risk of thrombotic events, including arterial and venous thrombosis. The significance of these antibodies can be summarized as follows:
- Elevated aCL antibodies have been linked to an increased risk of thrombosis, particularly in individuals with autoimmune diseases such as systemic lupus erythematosus (SLE) 2, 3.
- A 10-unit increase in aCL IgG titre was associated with an odds ratio of 1.07 for arterial thrombotic events and 1.06 for venous thrombotic events 2.
- The presence of multiple antiphospholipid antibodies, including aCL, was associated with an increased risk of thrombotic events 2, 3.
- However, not all studies have found a significant association between elevated aCL antibodies and thrombotic events, particularly in healthy individuals or those without autoimmune diseases 4, 5.
- Transient elevated aCL antibodies may be a trigger or biomarker of cardiac thrombotic events in younger atherosclerotic patients 6.
Clinical Implications
The clinical implications of elevated aCL antibodies can be summarized as follows:
- Individuals with elevated aCL antibodies may benefit from preventive anticoagulation, particularly if they have a history of thrombotic events or autoimmune diseases 2, 3.
- The presence of aCL antibodies should be considered in the diagnosis and management of thrombotic events, particularly in individuals with autoimmune diseases or a family history of thrombosis 2, 3.
- Further research is needed to fully understand the significance of elevated aCL antibodies and their role in thrombotic events 4, 5.