Antiphospholipid Syndrome Treatment Guidelines

Introduction to Treatment Approaches

The American College of Rheumatology recommends long-term warfarin with target INR 2.0-3.0 for thrombotic APS, combined low-dose aspirin plus prophylactic-dose LMWH for obstetric APS, and prophylactic aspirin alone for asymptomatic antiphospholipid antibody-positive patients 1, 2.

For venous thrombosis in APS, warfarin with target INR 2.5 is the gold standard for long-term anticoagulation, with a duration that is typically indefinite given persistent antibody presence and ongoing thrombotic risk 1, 2.
For arterial thrombosis in APS, warfarin with target INR 2.5 plus low-dose aspirin is recommended, with some guidelines suggesting higher intensity anticoagulation for arterial events 1, 2.
For obstetric APS, combined low-dose aspirin and prophylactic-dose heparin is strongly recommended, with aspirin started before 16 weeks gestation and continued through delivery, and prophylactic-dose anticoagulation continued for 6-12 weeks postpartum 1, 2, 6, 7, 8.
Hydroxychloroquine may be conditionally added to standard therapy for patients with primary APS, as recent studies suggest decreased complications 1, 2, 6, 8.

High-risk antibody profiles, including triple-positive, double-positive with LAC, and isolated LAC positivity, require more aggressive management 3, 6.
Low-risk profiles, including isolated anticardiolipin or anti-β2GPI at low-medium titers, may require less intensive management 3.

For patients failing standard therapy, hydroxychloroquine as adjunctive therapy, increasing target INR range for warfarin, and aggressive triple therapy with anticoagulation, glucocorticoids, and plasma exchange for catastrophic APS may be considered 1, 2, 3, 5.

Direct oral anticoagulants should never be used in APS patients, particularly triple-positive patients, due to excess thrombotic events compared to warfarin 3, 4, 5.
Anticoagulation should not be discontinued prematurely, as antiphospholipid antibodies typically persist and thrombotic risk remains elevated 4.
Estrogen-containing contraceptives should be avoided in women with positive antiphospholipid antibodies due to significantly increased thrombosis risk 5.
Thrombocytopenia does not reduce thrombotic risk in APS, and anticoagulation should not be withheld based on thrombocytopenia alone unless critically low or active bleeding present 3.
INR monitoring may be unreliable during sepsis, but therapeutic anticoagulation should be continued unless active bleeding or specific contraindication exists 3.
Antibody persistence should be confirmed, as diagnosis requires positive antibodies on two occasions at least 12 weeks apart 3, 4, 5.