Волчаночный антикоагулянт соотношение LA1/LA2 (скрининг/подтверждение)

The Lupus Anticoagulant (LA) assay assesses patients with unexplained venous or arterial thrombosis and pregnancy loss. It helps determine whether a prolonged activated partial thromboplastin time (aPTT) is due to a phospholipid-dependent inhibitor (lupus inhibitor) rather than a specific coagulation factor inhibitor. In combination with anticardiolipin and anti–β2‑glycoprotein I antibodies, LA testing supports the diagnosis of antiphospholipid syndrome (APS). When initially positive, testing is used to document persistence of lupus anticoagulant on follow-up and is often performed as part of a lupus anticoagulant panel.

Lupus anticoagulants are autoantibodies directed against phospholipids and/or phospholipid‑binding proteins. Phospholipids are integral to coagulation, providing platelet surface platforms that facilitate activation of multiple clotting factors during vascular or tissue injury. The antibodies were first described in systemic lupus erythematosus but may also occur in other autoimmune conditions, in AIDS, with inflammatory disorders, in malignancy, and in individuals taking phenothiazines, procainamide, or Fansidar. Presence of lupus anticoagulant is associated with an increased risk of both venous and arterial thrombosis, most commonly deep vein thrombosis. Occlusive thrombi can impair blood flow and lead to myocardial infarction, pulmonary embolism, and spontaneous pregnancy loss, particularly during the second and third trimesters. There is no single definitive assay for lupus anticoagulant. Detection typically involves a sequence of phospholipid‑dependent screening tests followed by confirmatory studies to verify or exclude an LA effect. Lupus anticoagulant is one of the three principal antiphospholipid antibodies linked to thrombotic risk; patients with antiphospholipid syndrome (Hughes syndrome) have one or more of these antibodies.