In systemic lupus erythematosus, to assess risk for thrombotic events and spontaneous abortion, which test should be ordered?

• A. Complete blood count
• B. PT/INR
• C. Bleeding time
• D. Anti-phospholipid antibodies

Answer: (D)

Antiphospholipid antibodies signal antiphospholipid syndrome, which markedly increases the risk of blood clots and pregnancy loss in systemic lupus erythematosus. Ordering an anti-phospholipid antibody panel—lupus anticoagulant, anticardiolipin, and anti-β2 glycoprotein I—directly assesses this risk and helps guide management, including considerations for anticoagulation in pregnancy or during thrombotic events. These antibodies are tied to both venous/arterial thrombosis and miscarriage, so identifying them provides the most relevant information for preventing these outcomes. In contrast, a complete blood count, PT/INR, or bleeding time measures general hematologic or coagulation aspects but does not specifically predict thrombotic risk or spontaneous abortion related to antiphospholipid syndrome.