T淋巴细胞异常活化及免疫炎性细胞因子分泌亢进是介导RA免疫炎性损伤的关键因素。本课题组前期对RA患者T细胞负性共刺激分子的研究和相关文献报道提示：BTLA/HVEM/LIGHT信号通路可能是RA患者免疫炎性损伤的关键信号通路。近年研究也证实miRNA与T细胞异常活化和体内免疫相关炎症反应密切相关，结合本课题组前期研究证实miR-499前体上的SNP位点与RA患者体内炎症水平密切相关，并且miR-499对BTLA 3'UTR区具有极强抑制作用，我们推测：miR-499抑制BTLA表达，通过BTLA/HVEM/LIGHT信号通路介导RA的免疫炎性损伤。本研究拟观察RA患者体内miR-499和BTLA/HVEM/LIGHT共刺激信号通路相关分子表达水平，并揭示miR-499通过调控BTLA/HVEM/LIGHT信号通路参与RA免疫炎性损伤的机制，为明确RA的炎症状态寻找的新的生物学标记物。

The abnormal activation of the T cell and abundantly secreted inflammatory factor was a key factor that would mediate immune inflammatory injury in RA. Combining our previous research on negative costimulatory molecule in T cell of RA and the relevant literature published recently, we found out that the BTLA/HVEM/LIGHT signal pathway may be a key signal pathway mediated immune inflammatory injury in RA. Besides, it was also shown in recent researches that miRNA and T cell abnormal activation and abnormal immune inflammation were closely related. Moreover, our previous studies also confirmed that the SNP of pre-miR - 499 and the level of inflammation in RA is closely related, and miR - 499 has a strong inhibition on BTLA 3'UTR. Therefore, we conjectured that miR-499 can inhibit the expression of BTLA which mediated immune inflammatory injury in RA through the BTLA/HVEM/LIGHT signal pathway. This research will observe the level of miR - 499 and related molecular of BTLA/HVEM/LIGHT costimulatory signal pathway and reveal that miR-499 can media the immune inflammatory injury in RA through the BTLA/HVEM/LIGHT costimulatory signal pathway. This research will contribute to looking for new biomarkers for the inflammatory level of RA .