ABSTRACT
Objective To investigate the diagnostic value of peptidylarginine deaminase-4 (PADI-4)detected in patients with rheumatoid arthritis (RA).Methods The levels of PADI-4,anti-CCP antibodies,AKA and APF were detected by ELISA in serum samples from 58 patients with RA,40 other rheumatic disease and 30 healthy individuals.The indicators were evaluate by application of ROC curve analysis,analysis of variance and correlation.Results PADI-4 serum level(2.653±2.719 U/L) of patients with RA was significantly higher than other rheumatic diseases group (0.872 ± 0.292 U/L)and the healthy group (0.793±0.243 U/L),the difference was statistically significant (t=22.732,35.371,P<0.01).Receiver operator curve analysis (ROC)showed an opitium cut off level for PADI-4 at 1.284 U/L,the sensitivity of PADI-4 was 62.1%.The specificity was 91.4% in RA.There was no significant difference between the positive rate of PADI-4 (62.1%)and APF (50%),AKA (56.9%)(χ2=0.322,P=0.570;χ2=1.715,P=0.190),and there was asignificant difference between PADI-4 and anti CCP antibody (χ2=4.161,P=0.041);a positive correlation between PADI-4 and APF,AKA (r=0.652,0.666, P<0.01),PADI-4 and between anti CCP antibody showed no correlation (r=0.122,P=0.357).Conclusion PADI-4 was significantly increased in serum of RA patients in part,PADI-4 has good sensitivity and specificity of RA,a new diagnostic markers might become independent of antibody against CCP in RA.