CCP

The cyclic citrullinated peptide antibody (CCP) test is a relatively new assay that detects the presence of citrulline antibodies in the blood. These autoantibodies are proteins produced by the immune system in response to a perceived threat from citrulline. An unusual amino acid, citrulline is produced when the amino acid arginine is altered. There is speculation that the conversion of arginine to citrulline may play a role in the autoimmune inflammatory process seen in the joints of those with Rheumatoid arthritis (RA).

RA is a chronic systemic autoimmune disease that causes inflammation, pain, stiffness, and destructive changes in the hands, feet, and other joints throughout the body. There are a variety of treatments available to minimize the complications of RA, but they depend on making an accurate diagnosis and on beginning treatment before the development of significant joint damage. Rheumatoid factor (RF) has been the primary blood test used to detect RA and distinguish it from other types of arthritis and other inflammatory processes. However, the sensitivity and specificity of RF are not ideal; it can be negative in patients who have clinical signs of RA and positive in patients who do not. Studies have shown that CCP has a sensitivity and specificity that is equal to or better than RF and is more likely to be positive with early RA.

According to the American College of Rheumatology (ACR), CCP antibodies may be detected in about 50-60% of patients with early RA, as early as 3-6 months after the beginning of symptoms. Early detection and diagnosis of RA allows doctors to begin aggressive treatment of the condition, minimizing the associated complications and tissue damage.

A blood sample is obtained by inserting a needle into a vein in the arm.

No test preparation is needed.