What is an Anticardiolipin (ACL) antibody?

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Last updated: May 21, 2025View editorial policy

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From the Guidelines

Anticardiolipin antibody is a type of autoantibody that targets cardiolipin, a phospholipid found in cell membranes, and is associated with an increased risk of blood clots, recurrent miscarriages, and other pregnancy complications. The presence of anticardiolipin antibodies in the bloodstream can interfere with the normal clotting process, leading to thrombotic events, and their prevalence ranges from 1% to 6.5% in the general population 1. These antibodies are commonly tested for when diagnosing antiphospholipid syndrome, a disorder that causes abnormal blood clotting, and testing typically involves a blood test that measures IgG, IgM, and sometimes IgA anticardiolipin antibodies. Some key points to consider about anticardiolipin antibodies include:

  • They are more commonly found in the elderly and patients with lupus 1
  • The association between anticardiolipin antibodies and stroke is strongest for young adults (<50 years of age) 1
  • Treatment for patients with anticardiolipin antibodies depends on their clinical situation but often includes anticoagulant medications like aspirin, heparin, or warfarin to prevent clotting complications, especially during pregnancy or after a thrombotic event. According to the guidelines for the prevention of stroke in patients with stroke or transient ischemic attack, there is no significant difference in the risk of stroke recurrence between patients treated with warfarin or aspirin 1. Overall, the management of patients with anticardiolipin antibodies should be individualized and based on their specific clinical situation, with a focus on preventing thrombotic events and improving outcomes.

From the Research

Definition and Characteristics of Anticardiolipin Antibody

  • Anticardiolipin antibody (ACA) is a type of autoantibody and one of the antiphospholipid antibodies (aPLs) 2
  • ACA targets phospholipids with a negative charge on platelets and endothelial cell membranes 2
  • It is commonly found in systemic lupus erythematosus and other autoimmune diseases, and is closely associated with thrombosis, thrombocytopenia, and spontaneous abortion 2

Clinical Significance and Diagnosis

  • Antiphospholipid syndrome (APS) is a prothrombotic condition characterized by the persistent presence of antiphospholipid antibodies (aPL), including ACA 3
  • The diagnosis of APS requires both clinical and laboratory classification criteria, including the detection of ACA and other aPL antibodies 4
  • Various assays are available for detecting ACA, including enzyme-linked immunosorbent assay (ELISA) and chemiluminescence-based panels 3, 5
  • The sensitivity and specificity of these assays can vary, and some may be more specific than others 5, 6

Laboratory Testing and Assays

  • Laboratory testing for ACA includes solid-phase assays, such as ELISA, and chemiluminescence-based panels 3, 4
  • These assays can detect IgG and/or IgM subclasses of ACA, as well as other aPL antibodies, such as anti-β2 glycoprotein I antibodies 3, 4
  • The use of fluorescence enzyme immunoassay (EliA) has been investigated for the diagnosis of APS, with varying sensitivity and specificity reported 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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