SLE & antiphospholipid syndrome flashcards
17 high-yield MRCP Part 1 cards from the Intellect Medicos Rheumatology course. Try to answer each question before you open it — then study them properly with spaced repetition, which brings each card back just before you would forget it.
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SLE is associated with HLA-DR2/DR3 and with inherited deficiency of early complement components such as ______.
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C1q, C2 and C4
Why? Early complement helps clear apoptotic debris and immune complexes; without it, nuclear antigens drive autoimmunity.
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Which antibody is the best screening test for SLE?
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Antinuclear antibody (ANA).
Why? ANA is positive in almost all patients with SLE (highly sensitive) but is also found in many other conditions and healthy people (not specific).
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Which antibody is the most specific for SLE but has low sensitivity?
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Anti-Smith (anti-Sm).
Why? A positive anti-Sm strongly supports SLE, but most patients with SLE are negative for it.
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In SLE, disease activity is tracked with ______ titres, which rise in flares, and C3 and C4 levels, which fall in flares.
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anti-dsDNA
Why? Complement is consumed by immune complexes in active disease, especially lupus nephritis.
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In SLE, disease activity is tracked with anti-dsDNA titres, which rise in flares, and ______ levels, which fall in flares.
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C3 and C4
Why? Complement is consumed by immune complexes in active disease, especially lupus nephritis.
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What is the most common cardiac manifestation of SLE?
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Pericarditis.
Why? SLE can also cause myocarditis and Libman–Sacks (sterile verrucous) endocarditis.
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Which drug should all patients with SLE receive unless contraindicated?
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Hydroxychloroquine.
Why? It reduces flares and organ damage and improves survival; patients also need sun protection and retinal screening.
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Which drug is the backbone of first-line induction for active proliferative (class III/IV) lupus nephritis, and what is used for maintenance (BSR 2026)?
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Mycophenolate, combined with belimumab, a calcineurin inhibitor (voclosporin or tacrolimus) or obinutuzumab, plus steroids and hydroxychloroquine. Maintenance: continue the mycophenolate-based regimen for at least 3 years.
Why? Renal biopsy classifies the nephritis and guides treatment. Azathioprine is the maintenance option if mycophenolate cannot be taken or pregnancy is planned.
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Which maternal antibody causes congenital heart block (neonatal lupus)?
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Anti-Ro (SSA) antibody.
Why? Anti-Ro crosses the placenta and damages the fetal conducting system; pregnancies are monitored with fetal echo.
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A woman with SLE on mycophenolate plans pregnancy. Which immunosuppressant is compatible with pregnancy as a replacement?
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Azathioprine (hydroxychloroquine and prednisolone are also continued as needed).
Why? Mycophenolate, methotrexate and cyclophosphamide are teratogenic. BSR advises stopping mycophenolate at least 6 weeks before trying to conceive.
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Which antibody is characteristic of drug-induced lupus?
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Anti-histone antibodies.
Why? Drug-induced lupus is milder than SLE, rarely affects kidneys or brain, and resolves when the drug is stopped.
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Name three drugs that cause drug-induced lupus.
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Any three: procainamide, hydralazine, isoniazid, minocycline, methyldopa, chlorpromazine, phenytoin, sulphonamides.
Why? Procainamide and hydralazine are the highest-risk drugs; slow acetylators are more susceptible.
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What is the first-line management of discoid lupus erythematosus?
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Strict sun protection plus potent topical corticosteroids.
Why? Topical calcineurin inhibitors are an alternative; hydroxychloroquine is the main systemic option for extensive disease.
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Which antiphospholipid antibody prolongs the APTT and is most strongly associated with thrombosis?
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Lupus anticoagulant.
Why? It interferes with phospholipid-dependent clotting tests in the laboratory, yet in the body it is prothrombotic.
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What is the long-term treatment after a first venous thrombosis in antiphospholipid syndrome?
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Lifelong warfarin, target INR 2–3.
Why? With recurrent thrombosis on warfarin, the slides advise adding aspirin or aiming for a higher INR (3–4).
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Why are DOACs generally avoided in antiphospholipid syndrome?
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They carry a higher risk of recurrent (especially arterial) thrombosis than warfarin, particularly in triple-positive patients.
Why? The MHRA advises against DOACs in APS, especially triple-positive disease (lupus anticoagulant, anticardiolipin and anti-β2-glycoprotein I).
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How is antiphospholipid syndrome managed during pregnancy?
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Low-dose aspirin plus LMWH (prophylactic dose for obstetric APS; therapeutic dose if there has been previous thrombosis).
Why? Warfarin is teratogenic, so it is switched to LMWH; the combination reduces miscarriage and pre-eclampsia risk.