ABSTRACT
To investigate rheumatoid arthritis [RA] for the diagnostic role of anti-cyclic citrullinated peptide antibody [anti-CCP] and antifilaggrin antibody [AFA] in comparison with RF and matrix metalloproteinase-3 [MMP-3]. A total of 60 RA patients and 50 other rheumatic disease patients were included in the study. We used a second generation enzyme-linked immunosorbent assay [ELISA] kit for the detection of anti-CCP. We constructed recombinant human filaggrin, which was citrullinated in vitro with human peptidylarginine deaminase, and subsequently used it as the coating antigen for AFA-ELISA. The specificities of anti-CCP [87.3%] and AFA [93.5%] were superior to those of RF [80.4%] and MMP-3 [50.1%]. The sensitivity of anti-CCP [86.3%] was superior to all others. However, the sensitivity of AFA [66.9%] was inferior to those of RF [68.5%] and MMP-3 [72.6%]. ELISA detection of antibodies to citrullinated antigens, especially a second generation anti-CCP, showed higher discriminative ability than other assays, including RF, and would be useful to aid in the diagnosis of RA in clinical practice