From the Guidelines
Anti-CCP (anti-cyclic citrullinated peptide) antibodies are commonly used to diagnose Rheumatoid Arthritis (RA), as they have high specificity for the disease and can appear years before clinical symptoms develop. The use of anti-CCP testing is recommended in the evaluation of patients with undifferentiated peripheral inflammatory arthritis (UPIA), as it can help predict the diagnosis and prognosis of RA [ 1 ].
Key Points
- Anti-CCP testing is a specific blood test that detects antibodies against citrullinated proteins, which are often present in patients with RA.
- The test is particularly valuable because it has high specificity (95-98%) for RA, meaning a positive result strongly suggests the disease [ 1 ].
- Anti-CCP antibodies can appear years before clinical symptoms develop, making the test useful for early diagnosis.
- The test is typically ordered alongside rheumatoid factor (RF) testing, as using both tests improves diagnostic accuracy [ 1 ].
- Anti-CCP positivity also indicates a higher likelihood of developing more severe, erosive joint disease.
- The presence of these antibodies helps distinguish RA from other inflammatory arthritis conditions, allowing for earlier appropriate treatment to prevent joint damage and disability.
Diagnosis and Treatment
The 2012 update of the American College of Rheumatology recommendations for the treatment of RA suggests that the presence of anti-CCP antibodies is a factor to consider when determining the prognosis and treatment of the disease [ 1 ].
Recommendations
- Testing of rheumatoid factor (RF) and/or ACPA, including anti-CCP, should be performed in the evaluation of patients with UPIA [ 1 ].
- The use of anti-CCP testing can help identify patients who are at higher risk of developing more severe disease and may benefit from earlier and more aggressive treatment.
From the Research
Diagnosis of Rheumatoid Arthritis (RA)
- Anti-cyclic citrullinated peptide (anti-CCP) is used in the diagnosis of Rheumatoid Arthritis (RA) 2, 3, 4, 5, 6
- The presence of anti-citrullinated protein antibodies (ACPAs) in the serum is one of the immunological features of RA 2, 5
- Anti-CCP assay has been widely used in clinics for the diagnosis of RA, but up to 40% of RA patients are anti-CCP negative 2
Diagnostic Sensitivity and Specificity
- The diagnostic sensitivity for anti-CCP was 81.1% and the specificity was 100% 2
- The diagnostic sensitivity for anti-CCP and MCSM was 95.3% and the specificity was 94.4% 2
- The combination of MCSM and anti-CCP test has the highest AUC (0.971,95% CI: 0.946-0.996) 2
- The diagnostic specificity and positive predictive value (PPV) of anti-CCP2 assay were 94.9% and 87.8%, respectively 4
Clinical Use of Anti-CCP
- ACPAs have high diagnostic sensitivity and specificity for RA and recognize citrullinated epitopes from several proteins 5
- Anti-CCP antibodies may also have prognostic value, especially in relation to early treatment, although ACPAs' main function is to aid in the diagnosis of RA 5
- The presence of RF or anti-CCP autoantibodies contributes to the current RA classification criteria 3, 6