ACLA-1 Antibody

Definition and Clinical Significance of Anti-Cardiolipin Antibodies (ACLA)

ACLA are autoantibodies targeting cardiolipin, a phospholipid component of cell membranes. These antibodies are part of the antiphospholipid antibody family and are strongly associated with:

• Thrombosis: Venous (e.g., deep vein thrombosis) and arterial (e.g., stroke, myocardial infarction) .

• Pregnancy complications: Recurrent miscarriages, fetal growth restriction, and preterm delivery .

• Neurological manifestations: Encephalopathy, migraines, and ischemic optic neuropathy .

ACLA testing is performed via immunoassays (IgG/IgM) and is part of the diagnostic criteria for APS when paired with clinical symptoms .

Mechanisms and Pathophysiology

ACLA bind to β2-glycoprotein 1 (β2GP1), a cofactor required for antiphospholipid antibody activity. This interaction disrupts anticoagulant pathways, leading to:

• Hypercoagulability: Increased risk of clot formation via platelet activation and endothelial dysfunction .

• Placental pathology: Impaired trophoblast invasion and decidual vasculopathy, contributing to pregnancy loss .

Diagnostic and Laboratory Features

Epidemiology and Associations

• Prevalence: Present in 1–5% of the general population; higher in autoimmune diseases like SLE .

• APS Subtypes:

  • Type I: Venous thrombosis (most common) .

  • Type II: Arterial thrombosis .

  • Type V: Pregnancy morbidity .

Therapeutic Management

• Anticoagulation: Lifelong warfarin (target INR 2–3) or heparin for thrombotic APS .

• Pregnancy: Low-dose aspirin + prophylactic heparin to reduce miscarriage risk .

• Refractory Cases: Rituximab or complement inhibitors under investigation .

Key Research Findings

• ACLA Titers and Thrombosis: Higher titers correlate with recurrent thrombosis and obstetric complications .

• Neurological Links: No direct correlation between ACLA levels and encephalopathy, but elevated titers may indicate severe disease .

• Infection-Induced ACLA: Transient ACLA positivity occurs in Lyme disease and viral infections, often without clinical APS .

Unresolved Questions

• Prognostic Value: Role of IgA ACLA and anti-β2GP1 antibodies in APS subtypes .

• Treatment Durability: Optimal duration of anticoagulation in seronegative APS .