[The changes of CD4(+) CD25(high) regulatory T cells in the course of rheumatoid arthritis and their significances].

AIM: To explore the percentages of CD4(+) CD25(high) regulatory T cells in peripheral blood or synovial fluid from patients with rheumatoid arthritis (RA) on different stages, and to study their correlations with the activity of the disease. METHODS: Peripheral blood lymphocytes were obtained from the patients with active RA who had received no previous disease modifying (DMARDs) therapy(n=11), from individuals with stable, well-controlled RA (n=12), from subjects whose disease were poorly improved after DMARDs therapy(n=9), and from healthy controls(n=8). The frequencies of CD4(+) CD25(high) T cells were quantified by using flow cytometry(FCM). Meanwhile, the correlations between the percentage of CD4(+) CD25(high) T cells and the level of Anti-CCP antibody, CRP, ESR and RF were also investigated. Paired blood and synovial fluid was analysed in a small group of RA and other patients. RESULTS: There was a smaller proportion of CD4(+) CD25(high) T cells in the peripheral blood of the active RA patients(mean 5.24%) and poorly-improved RA patients(mean 6.43%) than in patients with stable well-controlled RA or in healthy controls(mean 11.79% and 17.17%, respectively, P<0.01 in each case). The frequency of CD4(+) CD25(high) T cells from RA was negatively associated with Anti-CCP antibody(58.0 Ru/mL), ESR(38.8 mm/h) and CRP(2.73 mug/L), (P<0.05 for each). On contrast, The frequency of CD4(+) CD25(high) T cells from healthy controls was not significantly correlated with the level of Anti-CCP antibody(<5.0 Ru/mL), ESR(4.67 mm/h), CRP(0.15 mug/L) and RF(1.37) (all P>0.1). The percentage of CD4(+) CD25(high) regulatory T cells from synovial fluid of RA patients (24.32%) was significantly lower than that of AS patients(30.24%) (P<0.05). CONCLUSION: The results demonstrate a smaller CD4(+) CD25(high) regulatory T cell population in peripheral blood of individuals with active RA prior to disease modifying treatment and with poorly-improved RA, and this is negatively associated with the activity of the disease.