类风湿关节炎患者外周血、滑液及滑膜组织中自然杀伤细胞的特征

目的探讨自然杀伤细胞（NK）在类风湿关节炎（RA）中的特征以及在疗效判断中的作用。方法采用流式细胞仪在单个细胞水平分析RA患者外周血、滑液与滑膜组织中NK细胞的数量。分析NK细胞中信号分子的改变以及产生细胞因子的能力，观察经肿瘤坏死因子（TNF）单克隆抗体治疗后RA患者外周血中NK细胞数量的变化与疗效之间的相关性。结果与健康对照者相比，RA患者外周血中CD3^-CD56^＋NK细胞的数量显著减少（8．95±3．72vs.5．31±5．07，P〈0．05）。RA患者滑液与滑膜组织中CD3^-CD56^＋、CD3^-CD247^＋NK细胞的数量均显著少于相应的外周血（P〈0．05），同时这些细胞中信号分子CD247表达的强度也显著降低。IL-12联合IL-18刺激使1．4％的RA外周血单个核细胞产生干扰素γ，其中1．1％为NK细胞产生；肉豆蔻酸酯和钙离子载体可以使15．33％的单个核细胞产生干扰素γ，其中13．87％为T淋巴细胞产生，NK细胞占1．47％。经TNF单克隆抗体治疗14周后，临床判定为良好反应和中度反应的5例患者中4例外周血中NK细胞数目增加，而治疗反应差的2例患者中NK细胞数量增加或减少各1例。结论RA患者循环与炎症部位中NK细胞的数量显著减少，这些细胞的信号传导和细胞因子产生能力低下；NK细胞的低下状态与所处环境中的炎症程度有关，TNF单克隆抗体治疗在改善患者疾病活动性的同时，使外周血中NK细胞呈增加趋势，NK细胞可能成为疗效判断的一项指标。

Characterizations of Natural Killer Cells in Peripheral Blood,Synovial Fluid and Membranl of Patients with Rheumatoid Arthritis

Objective To explore the characterizations of natural killer （NK） cells in rheumatoid arthritis （RA） and potential roles in assessing the response to treatment. Methods Flow cytometric analysis was performed to look at the numbers of NK cells in peripheral blood, synovial fluid, synovial membrane, expression of signalling molecule and cytokine-producing capacity of NK cells. The correlation between the change of NK cells and efficacy to monoclonal antibody against tumor necrosis factor （TNF） in the treatment of active RA was also studied. Results Compared to healthy controls, the number of peripheral blood CD3^-CD56^＋ NK cells was significantly decreased （8.95 ± 3.72 vs. 5.31± 5.07, P 〈 0.05）. The numbers of CD3^-CD56^＋ and CD3^-CD247^＋ NK cells were dramatically decreased in synovial fluid and synovial membrane compared to the paired peripheral blood in RA patients （P 〈 0.05）. The expression of signalling molecule CD247 was also down-regulated in RA synovium. 1.4% and 15.33% of the peripheral blood mononuclear cells produced interferon 7 when stimulated respectively by interleukin-12 combined with interleukin-18 and phorbol myristate acetate combined with ionomycin, however the significant increase of interferon γ produced by NK ceils was not shown. After commencing TNF monoclonal antibody treatment for 14 weeks, increased NK ceils was observed in 4 out of 5 good responders or moderate responders. Conclusions The numbers of NK cells in both circulation and inflammation sites were decreased, meanwhile the capacity of signalling transduction and cytokine-production were also impaired in RA. These phenomena were correlated to the chronic inflammation in RA. With clinical improvement after TNF monoclonal antibody therapy, the tendency of increased peripheral NK cells was observed. Monitoring NK cells could be helpful for efficacy assessment.