Anti Phospholipid Syndrome (APS) Profile

The APS profile is a combined panel that detects the three main families of antiphospholipid antibodies: lupus anticoagulant (LA, a functional clotting test), anticardiolipin antibodies (aCL — IgG and IgM), and anti-beta-2-glycoprotein-1 antibodies (anti-β2GP1 — IgG and IgM). These autoantibodies target phospholipid-binding proteins on cell membranes and disrupt the normal balance between clot formation and breakdown.

A full panel is needed because each test catches different patients — about a third of APS patients are positive for only one of the three. The 2023 ACR/EULAR APS classification criteria require persistence (positive on two occasions ≥12 weeks apart) and combine laboratory criteria with clinical features (thrombosis, pregnancy morbidity).

Antiphospholipid syndrome (APS) is a major treatable cause of unprovoked blood clots (deep vein thrombosis, pulmonary embolism, stroke in young adults), recurrent miscarriage, and pregnancy complications (stillbirth, severe pre-eclampsia, intrauterine growth restriction). In Indian clinical practice it is an essential workup in: any young adult with a stroke or unusual-site thrombosis (cerebral venous sinus, splanchnic, portal vein), women with three or more first-trimester miscarriages or one late pregnancy loss, and patients with lupus considering pregnancy.

Diagnosing APS changes management dramatically. Patients with confirmed APS and prior thrombosis need lifelong anticoagulation (warfarin is preferred over DOACs for triple-positive patients). Pregnant women with APS are usually managed on aspirin + low molecular weight heparin to dramatically reduce miscarriage rates. The diagnosis also identifies risk for catastrophic APS — a rare but life-threatening multi-organ thrombotic crisis.

No fasting required for the antibody parts of the panel. For lupus anticoagulant (LA) — ideally tested before starting anticoagulation, because heparin and DOACs (rivaroxaban, apixaban) interfere with LA detection. If you are already on these drugs, your doctor may delay LA testing or use specialised mixing studies. Tell your phlebotomist about all anticoagulants you take.