Catastrophic APS — RACP Adult Medicine MCQ

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HardRheumatologyCatastrophic APSRACP Adult Medicine

A 35-year-old woman with antiphospholipid syndrome on warfarin develops catastrophic APS (CAPS) with simultaneous multiorgan thrombosis (renal failure, stroke, and pulmonary embolism) over 48 hours. What is the recommended triple therapy for CAPS?

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Correct answer: B — Eculizumab alone

Catastrophic APS (CAPS) is a rare, life-threatening variant of APS characterised by simultaneous thrombotic involvement of ≥3 organs within 1 week. Mortality is ~30% even with treatment. The recommended 'triple therapy' is: (1) therapeutic anticoagulation (heparin initially), (2) plasma exchange (to remove pathogenic antiphospholipid antibodies), and (3) high-dose corticosteroids (IV methylprednisolone 1 g daily for 3 days). IVIg may be added as a fourth agent. Rituximab and eculizumab (complement inhibition) are used for refractory CAPS. Trigger identification and treatment (infection in 40% of cases) is essential.

Reference: eTG – 2025 – Haematology; CAPS Registry – 2023