Study on the imbalance of Th17 cells/CD4 + CD25 + FoxP3 + regulatory T cells in patients with rheumatoid arthritis

Objective To observe the relationship between balance of peripheral blood Th17 cells and CD4 + CD25 + FoxP3 + regulatory T(Treg) cells in patients with rheumatoid arthritis (RA), and to analyze the role of Th17/Treg cell imbalance in the pathogenesis of RA. Methods Four-color flurescence flow cytometry was used to detect the CD3,CD8,IL-17 and CD4,CD25, FoxP3 markers in the peripheral blood of 47 patients and 39 healthy volunteers(HVs) . The proportions of Th17 cells and CD4 + CD25 + FoxP3 + regulatory T cells were compared between the two groups. IL-6, IL-23 and IL-17 in sera of these subjects were tested by ELISA.Results The quantity of CD3 + CD8-IL-17 + cells in RA patients was significantly higher than those in normal control[(1. 12 ± 0. 38) % vs. (0.68 ± 0.29) %; t = 1.83, P ＜ 0.05)]and the proportions of CD4 + CD25 +FoxP3+ cells were significantly lower in RA group compared with HV group[(2.74 ±0.71)% vs. (4.69 ±1.23) %; t = - 2. 94, P ＜ 0.05]. Meanwhile , IL-6, IL-23 and IL-17 in sera of RA were (13.5 ± 3.7)ng/L, (71 ± 19) ng/L and (122 ± 33) ng/L respectively. These three cytokines in healthy controls were (4.6±0.9) ng/L (t =6.24, P＜0.01),(25 ±6) ng/L (t =14.37,P＜0.01), and (37±9) ng/L (t =19.01,P＜0. 01) respectively. IL-6,IL-23 and IL-17 increased significantly in RA patients as compared with healthy donors. Conclusion This study suggested that abnormality of Th17 and CD4 + CD25 + FoxP3 + Tregs might depend on the increased IL-6 and IL-23 and it may play a critical role in the incidence of RA. Key words: Rheumatoid Arthritis;  Th17;  Treg;  Cytokine;  Immune homeostasis