What antibody profile defines triple-positive APS?

Triple positive: lupus anticoagulant + anti-cardiolipin IgG/IgM ≥40 GPL/MPL + anti-beta2-glycoprotein I IgG/IgM ≤40 units; triple positivity carries the highest thrombotic and pregnancy morbidity risk; recurrence rate >30%/year without anticoagulation.

What INR target is recommended for arterial vs venous APS?

Venous APS first event: warfarin INR 2-3; recurrent venous or arterial APS: INR 3-4 or high-intensity therapy; TRAPS trial showed INR 3-4 not superior to 2-3 for recurrence; individualized based on triple positivity and prior event type.

Why are DOACs inferior to warfarin in high-risk APS?

TRAPS, ASTRO-APS, and DIRECT trials: rivaroxaban associated with higher arterial thrombosis and MACE rates vs warfarin in triple-positive APS; DOACs may be used in single/double positive low-risk APS with venous events only.

What obstetric APS management prevents recurrent pregnancy loss?

Aspirin 75-100 mg/day + low molecular weight heparin from positive pregnancy test to 6 weeks postpartum; live birth rate increases from ~25% untreated to >70% treated; hydroxychloroquine added in SLE-APS; refractory cases: IVIG, pravastatin, hydroxychloroquine.

What is catastrophic APS (CAPS) and how is it treated?

CAPS: thrombotic microangiopathy affecting ≥3 organs within a week with aPL positivity; 30% mortality; treatment: anticoagulation (UFH) + high-dose steroids + IVIG + plasma exchange; rituximab for refractory CAPS; trigger identification and removal essential.

Antiphospholipid Syndrome Thrombotic Risk and Anticoagulation Calculator

Calculates Global APS Score (GAPSS) for thrombotic risk in antiphospholipid syndrome, identifies triple-positive criteria patients, and guides anticoagulation intensity (INR 2-3 vs 3-4 vs direct oral anticoagulants).

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