Anti-CCP antibodies are better than rheumatoid factor for diagnosing rheumatoid arthritisBMJ 2007; 334 doi: https://doi.org/10.1136/bmj.334.7606.1245-b (Published 14 June 2007) Cite this as: BMJ 2007;334:1245
Serum concentrations of antibodies against cyclic citrullinated peptide (anti-CCP) seem to be just as sensitive and more specific than rheumatoid factor for diagnosing rheumatoid arthritis and predicting its progression.
A systematic review and meta-analysis included 37 studies that looked at the diagnostic accuracy of anti-cyclic citrullinated peptide antibodies and 50 studies that assessed the diagnostic accuracy of rheumatoid factor. While the sensitivities were 67% (95% CI 62% to 72%) and 69% (65% to 73%) for anti-cyclic citrullinated peptide antibodies and IgM rheumatoid factor, respectively, the specificity for anti-cyclic citrullinated peptide antibodies was 95% (94% to 97%) , compared with 85% (82% to 88%) for IgM rheumatoid factor.
Early diagnosis and treatment of rheumatoid arthritis are crucial to avoid irreversible damage to the joints. Because rheumatoid factor can be present in the plasma of healthy people and people with autoimmune diseases other than rheumatoid arthritis, using anti-cyclic citrullinated peptide antibodies can be of great help in making the diagnosis. The authors propose that these antibodies should be officially recognised as a diagnostic marker, but also acknowledge that publication bias may have played a role in the favourable results.