The diagnostic value of anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis

Objective To explore the diagnostic value of anti cyclic citrullinated peptide (CCP) antibody (anti CCP) detected by ELISA in patients with rheumatoid arthritis (RA).Methods The synthesized CCP deduced from the known cDNA sequence was used as substrate in ELISA.The anti CCP was detected by ELISA in 294 RA,132 rheumatic diseases other than RA and 135 non rheumatic diseases.To compare the correlation among the anti CCP and APF (antiperinuclear factor),AKA (anti keratin antibody),RF (rheumatoid factor) and HLA DR4.Results One hundred and thirty seven (46 6%) RA sera,7 (5 3%) other rheumatic disease sera and 2 (1 8%) non rheumatic disease were found to be anti CCP positive by ELISA.The sensitivity of anti CCP was 46 6% with high specificity (96 9%) in RA.Anti CCP was associated with APF,AKA and HLA DR4 except RF.Conclusions Anti CCP presents a reasonable sensitivity (46 6%) with high specificity (96 6%) to RA and it is valuable to RA diagnosis.Anti CCP is associated with APF,AKA and HLA DR4 but not completely overlaps them.Anti CCP could be regarded as a new diagnostic marker in RA.