Expression and significance of peripheral blood cyclic citrullinated peptide antibody and CD4+ CD25+ regulatory T cells in rheumatoid arthritis

Abstract

Objective To investigate the significance of detecting cyclic citrullinated peptide (CCP) antibody and CD4+ CD25+ regulatory T cells (Treg) in rheumatoid arthritis (RA).Methods Fifty-four patients with RA as defined by ACR criteria were investigated as study group.The control group consisted of 20 healthy volunteers.The serum CCP antibody was detected by using enzyme linked immunosorbent assay (ELISA),the peripheral CD4+ CD25 + Treg were detected by using flow cytometry,and articular erosion was checked by using X-ray photograph.Results As compared with normal control group,the positive rate of serum CCP antibody (66.7％ ) was significantly increased (P ＜0.01 ),and that of peripheral blood CD4 + CD25 + Treg (3.41 ± 1.83 )％ was decreased significantly in RA group.There were no significant differences in the levels of CD4+ CD25+ Treg between the positive CCP antibody patients and the negative CCP antibody patients (P＞0.05),but there was significant difference in the rate of articular erosion (P ＜ 0.05).No significant correlation was found between the rate of articular erosion and the levels of CD4 + CD25 + Treg in the positive CCP antibody patients.Conclusion CCP antibody was a satisfactory marker for RA.Articular erosion occurred more possibly in positive CCP antibody RA patients than in negative CCP antibody patients,but it was irrelevant to the decrease of peripheral blood CD4 + CD25 + Treg. Key words: Cyclic citrullinated peptide antibody; Regulatory T cell; Rheumatoid arthritis