Evaluation of CD4+/CD25+/high/CD127low/- Regulatory T Cells in Rheumatoid Arthritis Patients.

BACKGROUND Rheumatoid arthritis (RA) is the most common inflammatory rheumatic disease of unknown etiology, determined by the destruction of articular cartilage and bone loss. The hallmark of RA is a defect in immune tolerance. Regulatory T cells (Treg) play a critical role in the protection of peripheral tolerance. OBJECTIVE To assess the percentage of Treg CD4+/CD25+/high/CD127low/- cells in peripheral blood of RA patients as compared with the healthy individuals. METHODS The number of Treg CD4+/CD25+/high/CD127low/- cells was assessed by multicolor flow cytometry. The clinical disease activity of RA patients was determined by disease activity score 28 (DAS-28). The correlation of DAS-28 and erythrocyte sedimentation rate (ESR) was evaluated along with Treg cells in peripheral blood of RA patients. RESULTS The percentage of Treg CD4+/CD25+/high/CD127low/- cells in peripheral blood of RA patients significantly decreased as compared with the healthy individuals (P= 0.0002). The percentage of Treg CD4+/CD25+/high/CD127low/- cells negatively correlated with DAS-28 and ESR. CONCLUSION This study concludes that the defect of Treg cells plays a vital role in the pathogenesis of this disease. Further studies are necessary to determine the role of Treg cells in the clinical course of rheumatoid arthritis.