Anti-CCP antibodies, a highly specific marker for (early) rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, destructive autoimmune disease affecting the joints. With more sophisticated and effective therapies becoming available and with the understanding that early intervention is crucial in preventing irreversible joint damage, it is more and more important to diagnose RA at a very early stage in the disease. To facilitate diagnosis during the early stages of the disease, when often not all clinical symptoms are manifest, a good serological marker is needed. Antibodies directed to citrullinated proteins provide this ability. The most sensitive assay to detect these antibodies is the so-called anti-cyclic citrullinated peptide (CCP) enzyme-linked immunosorbent assay (ELISA) assay. In this review, the diagnostic and prognostic potential and the general utility in clinical practice of anti-CCP antibodies are discussed. Furthermore, we elaborate on the mechanisms involved in the generation of citrullinated autoantigens and the possible role of the anti-CCP antibodies and their antigens in the disease.