Description
The cyclic citrullinated peptide antibody (CCP) test detects the presence of anti-citrulline antibodies in the blood. Citrulline is an unusual amino acid (protein building block), which is created when the amino acid arginine is altered. There is speculation that conversion of arginine to citrulline resulting in “citrullinated” proteins in the lining of joints, may be the target of anti-CCP antibodies in RA, which may contribute to inflammatory process in RA.