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.
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.
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).
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.