Which antibody is commonly used in evaluating rheumatoid arthritis and is highly specific?

Which antibody is commonly used in evaluating rheumatoid arthritis and is highly specific?

• A. Cyclic citrullinated peptide antibody
• B. Rheumatoid factor
• C. Antinuclear antibody
• D. Anti-dsDNA

Answer: (A)

Anti-cyclic citrullinated peptide antibodies are highly specific markers used in evaluating rheumatoid arthritis. Their presence strongly supports an RA diagnosis and can appear early, sometimes even when other tests like rheumatoid factor are negative. This high specificity helps differentiate RA from other inflammatory joint diseases and autoimmune conditions. In contrast, rheumatoid factor is less specific because it can be elevated in various diseases and in healthy individuals, especially with aging. Antinuclear antibodies point to a range of autoimmune diseases, most notably lupus, and anti-dsDNA is particularly associated with systemic lupus erythematosus, not RA.