系统性红斑狼疮与类风湿性关节炎患者外周负性共刺激分子PD-1与调节性T淋巴细胞免疫紊乱的研究

Objectives: To explore the balance state of peripheral regulatory T cells and effector T cells, as well as preliminarily learn the regulatory role of programmed death-1 (PD-1) on different T cell subsets in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Methods: 40 patients with SLE, 50 patients with RA and 19 healthy volunteers were included. Peripheral T cells subsets, CD4+CD25high regulatory T cells (Treg) and CD4+CD25low effector T cells (Teff), as well as the percentage of PD-1 on different lymphocyte subsets were all detected by flow cytometry. Results: ⑴ Compared with healthy control (HC), high percentage of peripheral CD3+CD8+T cells was the characteristics of SLE, and high percentage of CD3+CD4+T cells and high CD4/CD8 ratio were the features of RA. ⑵ Percentage of peripheral CD4+CD25high Treg cells and CD4+CD25low Teff cells in SLE and RA was lower than those in HC (only Treg cells significantly decreased, P<0.05)，Teff/Treg ratio strikingly increased compared with HC。⑶ Compared with HC, the percentage of PD-1 on CD3+T cells, CD3+CD4+T cells and CD3+CD8+T cells was all significantly increased in SLE and RA, and that in SLE was strikingly higher than that in RA（P<0.05）.⑷ The percentage of PD-1 on peripheral Treg cells or Teff cells was the lowest in RA (compared with HC or SLE, all P<0.05), and was highest in SLE (compared with HC, P>0.05) . conclusions：Negative costimulator PD-1 couldn't play an important role in immune suppression in SLE or RA patients. Low percentage of Treg cells was the critical factor in the disturbed immune in SLE; and the synergistic effects of low expression PD-1 on CD4+CD25+Treg cells and decreased Treg cells was one of important factors to cause the insufficient immune suppression in RA.