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Anti-Phospholipid Syndrome

Gautam Babu


  • Antiphospholipid antibodies (aPLs) = a heterogenous group of autoantibodies which interact with endothelial cells through binding of β2GPI receptor

  • APLs induce a procoagulant and proinflammatory endothelial phenotype arterial, venous, small vessel thromboembolic events, or pregnancy losses


  • Unexplained/recurrent venous, arterial, and/or small vessel thromboembolic events

  • Venous: DVT most common

  • Arterial: cerebral, renal, mesenteric, coronary, PE

  • Pregnancy morbidity: recurrent, unexplained spontaneous abortions, fetal loss, preterm birth due to preeclampsia, placental insufficiency

  • Other features: nonbacterial vegetations (Libman-Sachs endocarditis), thrombocytopenia, livedo reticularis


  • Revised Sapporo classification criteria: At least one of the clinical criteria and one of the laboratory criteria are met:
  • Vascular thrombosis (arterial, small vessel, or venous)

  • Pregnancy morbidity

  • Antiphospholipid lab testing: must be present on two or more occasions at least 12 weeks apart (NOT TESTED INPATIENT) Lupus anticoagulant, anticardiolipin antibody (IgG or IgM, medium or high titer) anti-beta-2 glycoprotein-I antibody (IgG or IgM)


  • Mainstay is anticoagulation for treatment and secondary prevention

  • Acute thromboembolism: Heparin gtt with bridge to warfarin

  • Secondary thrombosis prevention, anticoagulation with warfarin is preferred

  • Studies suggest that DOACs are less effective than warfarin

  • Goal INR 2-3 regardless of whether arterial or venous thromboembolism present

  • ASA 81 mg + warfarin for pts w/arterial events and risks for ASCVD

Catastrophic Anti-phospholipid Syndrome (CAPS)

Gautam Babu


  • Rapid development of thromboses in multiple small blood vessels in various organs resulting in multi-organ failure. Occurs in a small subset of patients with APS


  • Similar presentation to APS, but multiple organs are involved in a short period of time

  • Renal (hypertension, proteinuria, hematuria, acute renal failure), Pulmonary (ARDS, PE), Central Nervous System (encephalopathy, stroke, cerebral venous thrombosis), Cardiac (coronary thrombosis), and Cutaneous (livedo reticularis, acrocyanosis, purpura, ecchymosis, splinter hemorrhages, and necrosis resulting in ulceration)


  • Exclude other causes of small vessel occlusion: HIT, DIC or TMA

  • Definite dx= all 4 criteria met, probable dx=combination of criteria present

  • Evidence of involvement of three or more organs, systems, and/or tissues

  • Development of manifestations simultaneously or in less than a week

  • Confirmation by histopathology of small vessel occlusion in at least one organ or tissue

  • Laboratory confirmation of the presence of antiphospholipid antibodies


  • Anticoagulation: Heparin acutely. Warfarin once stable & no bleeding or recurrent thromboses

  • Pulse steroids with methylprednisolone x 3 days followed by prednisone

  • Severe cases may require PLEX/IVIG. Refractory CAPS may require rituximab or eculizumab

Last update: 2022-06-26 16:52:32