Review Question - QID 4804

Anti-cyclic citrullinated peptide antibodies (anti-CCP) are commonly used as a marker for the diagnosis and prognosis of rheumatoid arthritis (RA).

Immunological studies are commonly performed to investigate cases of suspected rheumatoid arthritis. Rheumatoid factor has historically been used as a primary marker for RA. However, in more recent years, the use of anti-CCP antibodies has shown to be as sensitive as, and more specific than, rheumatoid factor (RF) in early and fully established disease. In general, anti-CCP assays equate to a sensitivity of 50-75% and a specificity of 90-95%. High levels of anti-CCP have been shown to be indicative of a more erosive disease process and may be detected before the onset of arthritis.

Gardner and Kadel reviewed the laboratory studies most commonly used in rhuematologic diseases. Standard ordering for clinically suspected RA include Rf, anti-CCP, ESR/CRP as well as other markers of autoimmune diseases such as antinuclear antibodies, anticardiolipin antibodies and lupus anticoagulant, HLA-B27, and uric acid levels.

Illustration A shows the sensitivity and specificity of anti-CCP vs. RF in a variety of autoimmune diseases.

Incorrect Answers:
Answers 1,3-5: Anti-CCP is not routinely used to diagnose and monitor these conditions.