APS is an autoimmune condition associated with recurrent thrombosis. Suspect if history of unprovoked VTE, recurrent miscarriage.
Diagnosis - Antiphospholipid antibodies: lupus anticoagulant, anticardiolipin, or anti-ฮฒ2 glycoprotein I antibodies.
Pregnancy is managed with LMWH + aspirin.
Warfarin is used long-term in non-pregnant patients with prior thrombosis +/- aspirin
๐งฌ Pathophysiology
APS involves autoantibodies directed against phospholipid-binding proteins, especially ฮฒ2 glycoprotein I. These antibodies promote endothelial dysfunction, platelet activation etc.
The result is a hypercoagulable state, predisposing to arterial and venous thrombosis and placental insufficiency in pregnancy.
๐ Clinical Features
๐ Thrombotic Events
Venous thrombosis: DVT, PE - recurrent, unprovoked, young age
Arterial thrombosis: Stroke, MI, limb ischaemia
๐คฐ Pregnancy Morbidity
Recurrent miscarriage (especially in first trimester)
Pre-eclampsia / Eclampsia
Intrauterine growth restriction (IUGR)
Stillbirth or premature birth
๐งช Investigations
Antiphospholipid antibodies
Lupus anticoagulant (LA)
Anticardiolipin (aCL) antibodies
Anti-ฮฒ2 glycoprotein I antibodies
๐ Management
๐ง Non-Pregnant Patients
Warfarin (target INR 2.0โ3.0) for those with history of thrombosis
May increase INR target for recurrent thrombosis
Aspirin in addition, or may be used alone in antibody-positive patients without a history of thrombosis
๐คฐ Pregnancy Management
Low-dose aspirin + prophylactic LMWH from early pregnancy
Warfarin is contraindicated in pregnancy (teratogenic)
๐ Exam Clues & Clinchers
Young woman with recurrent first-trimester losses and history PE โ think APS
