Clinical significance of anti-cyclic citrullinated peptide (anti-CCP) antibodies in rheumatoid arthritis: Literature review

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease that principally affects synovial joints, leading to functional disability and significant morbidity and mortality. The hallmark of RA is the presence of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies. Based on the presence of anti-CCP antibodies, RA can be classified into two subsets: anti-CCP positive and anti-CCP negative RA, having distinct genetic and environmental risk factors and different pathogenesis. Early and accurate diagnosis of RA is the key to timely and appropriate management of the disease. Anti-CCP antibodies can be detected at an early stage of RA when symptoms are milder and incomplete or even absent, making these autoantibodies a useful serological marker for early diagnosis. Furthermore, the presence of anti-CCP antibodies can predict the development of joint erosions. Hence, RA patients with a potentially severe course may be selected for early aggressive treatment, which may reduce structural joints damage. In addition, anti-CCP antibodies are considered a useful biomarker for monitoring disease activity and therapy response. On the other hand, several studies in RA patients have focused on the diagnostic performances of second and third generations of anti-CCP antibodies, as well as their cut-off values that considerably differ between available assays, thereby emphasizing the need for harmonization of the cut-off values for low and high anti-CCP levels.