Anti-CCP and Cyclic Citrullinated Peptide Testing Are the Same
Yes, a cyclic citrullinated peptide (CCP) lab order and an anti-CCP test refer to the same diagnostic test—they both measure antibodies against cyclic citrullinated peptides in the blood. 1
Understanding the Terminology
The terms "anti-CCP" (anti-cyclic citrullinated peptide antibody) and "CCP antibody" are used interchangeably in clinical practice and refer to the identical laboratory test 1
The test specifically measures antibodies directed against citrullinated peptides or proteins, which are highly specific markers for rheumatoid arthritis 2, 3
The full technical name is "anti-cyclic citrullinated peptide antibody test," but it is commonly abbreviated as anti-CCP, ACPA (anti-citrullinated protein antibody), or simply CCP antibody 4, 5
Clinical Context and Diagnostic Performance
Anti-CCP demonstrates superior specificity (96-98%) for rheumatoid arthritis compared to rheumatoid factor (RF), which has only 70-85% specificity 1, 4
The test has moderate sensitivity of approximately 66-73.5% for RA, meaning it will miss about one-third of RA cases 1, 2, 6
Anti-CCP antibodies are detectable very early in the disease process, often before clinical manifestations are fully apparent, making them valuable for early diagnosis 4, 2
The diagnostic odds ratio for anti-CCP is 43.05, indicating that a patient with RA is 43 times more likely to test positive than a patient without RA 1
Ordering Considerations
When ordering this test, you may see it listed as "anti-CCP," "CCP antibody," "anti-cyclic citrullinated peptide," or "ACPA"—all refer to the same test 4, 5
Both anti-CCP and RF should be ordered together in the evaluation of patients with undifferentiated peripheral inflammatory arthritis, as they provide complementary diagnostic information 4, 5
The test uses an ELISA methodology with a synthetic cyclic peptide containing citrulline as the antigenic substrate 7
Common Pitfalls to Avoid
Do not assume a negative anti-CCP result excludes RA, as approximately 30-40% of RA patients are seronegative for anti-CCP 4, 5
Do not delay treatment waiting for positive serology, as seronegative RA has similar prognosis and requires the same aggressive management 5
Recognize that anti-CCP positivity is associated with more severe disease progression, worse radiographic outcomes, and higher risk of erosive disease 4, 2, 7