Antiphospholipid syndrome (APS)

Presentation of antiphospholipid syndrome

• Recurrent venous or arterial thrombosis
  • Venous more common than arterial
  • Arterial most commonly cerebral
• Recurrent foetal loss or miscarriage
• Can occur in association with SLE or rheumatoid arthritis (secondary) or alone (primary)

Pathogenesis of antiphospholipid syndrome

• Antibody-related (lupus anticoagulant, anti-cardioplipin, anti B2 glycoprotein)
• Underlying defect may  involve mammalian target of rapamycin complex (mTORC)
  • See NEJM 2014; 371:369-371

Diagnostic criteria for antiphospholipid syndrome (requires at least one clinical and at least one laboratory feature)

• One or more episodes of arterial, venous or small vessel thrombosis
• One or more foetal loss >10/40
• Three or more unexplained miscarriages at <10/40
• One or more pre-term (<34/40) due to eclampsia or placental insufficiency
• Lupus anticoagulant, anti-cardioplipin or anti B2 glycoprotein present on at least 2 occasions, 12 weeks apart

Treatment of antiphospholipid syndrome

• Treatment dose anticoagulation post-thrombotic event (usually life-long if significant)
• Consider low dose aspirin for prophylaxis
• In pregnancy
  • Prophylactic LMWH if no history of thrombosis
  • Treatment dose LMWH if history of thrombosis

Complications of antiphospholipid syndrome

• Catastrophic antiphospholipid syndrome (rare)
  • Acute thrombotic microangiopathy, multiple organ thrombosis, occasionally with skin necrosis