A young woman has a malar rash, arthralgia, photosensitivity and proteinuria. Which antibody is most specific for the likely diagnosis?
Answer and explanation
Correct answer: B. Anti-double-stranded DNA antibody
- Step 1: The multisystem features point to systemic lupus erythematosus. Step 2. Anti-dsDNA is highly specific and correlates with disease activity, and complement levels are often low, with hydroxychloroquine as a mainstay of treatment. Answer: Anti-double-stranded DNA antibody. Why not the others: Anti-centromere antibodies are associated with limited systemic sclerosis. Anti-Jo-1 is associated with polymyositis. Rheumatoid factor is nonspecific.
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