Which autoantibody is most specific for systemic lupus erythematosus?

Which autoantibody is most specific for systemic lupus erythematosus?

• A. Anti-dsDNA
• B. Anti-centromere
• C. Rheumatoid factor
• D. Anti-SSA

Answer: (A)

The key idea is how specific an autoantibody is for diagnosing systemic lupus erythematosus. Anti-dsDNA antibodies are highly specific for SLE; their presence strongly supports the diagnosis, especially when clinical features align, even though not every patient with SLE has them. In contrast, anti-centromere antibodies are more typical of limited systemic sclerosis (CREST), rheumatoid factor can be found in many conditions and even in healthy people, and anti-SSA is associated with Sjögren’s syndrome and can appear in SLE but is not as specific for SLE as anti-dsDNA. So anti-dsDNA stands out as the most specific autoantibody for SLE among the options.

The key idea is how specific an autoantibody is for diagnosing systemic lupus erythematosus. Anti-dsDNA antibodies are highly specific for SLE; their presence strongly supports the diagnosis, especially when clinical features align, even though not every patient with SLE has them. In contrast, anti-centromere antibodies are more typical of limited systemic sclerosis (CREST), rheumatoid factor can be found in many conditions and even in healthy people, and anti-SSA is associated with Sjögren’s syndrome and can appear in SLE but is not as specific for SLE as anti-dsDNA. So anti-dsDNA stands out as the most specific autoantibody for SLE among the options.