Antibodies to cyclic citrullinized peptide in rheumatoid arthritis

Abstract

Aim. To estimate a diagnostic value of antibodies to cyclic citmllinized peptide (CCP) in rheumatoid arthritis (RA). Material and methods. The study was made of 85 RA patients. Of them, 48 patients had early RA, i.e. of 8 month and less duration. The control group consisted of 35 patients with non-differentiated arthritis (NBA) and 8 healthy donors. Concentrations of CCP antibodies, rheumatoid factor (RF) IgM and RF IgA were measured with enzyme immunoassay (EIA). Results. The level of CCP antibodies in RA patients (76.3 ± 43.8; median 100.0 U/ml) was significantly higher than in NDA patients (25.1 ± 43.9; median 0.8 U/ml; p and 72%, 83%, respectively). Simultaneous tests for CCP antibodies, RF IgM and RF IgA led to a 93% specificity. CCP antibodies were detected in 50% patients seronegative by RF IgM and in 62% patients seronegative by IgA. Detection of CCP antibodies was closely associated with early RA (x2 = 30.8;p = 0.0001). Conclusion. The EI A for CCP antibodies is a sensitive and specific serological test for early RA diagnosis.

Keywords

• antibodies to cyclic citrullinized peptide
• rheumatoid factor
• rheumatoid arthritis