中文摘要：

目的观察唾液酸结合免疫球蛋白样凝集素-1（Siglec-1）在类风湿关节炎（RA）患者外周血单个核细胞（PBMCs）上的表达水平，并探讨其与RA疾病活动度的关系。方法分别采用流式细胞术及实时荧光定量反转录聚合酶链反应（RT-PCR）检测42例RA患者、28例骨关节炎患者和26名健康对照者外周血Siglec-1蛋白和mRNA表达，并将Siglec-1表达与28个关节疾病活动度评分（DAS28）以及超敏c反应蛋白（hs-CRP）作相关性分析。组间均数比较采用t检验，相关性分析采用Pearson相关分析。结果流式细胞仪检测发现，RA组Siglec-1阳性细胞占PBMCs比例为（15．2±7．6）％，明显高于骨关节炎组[（2．3±2．6）％]和健康对照组[（2．1±1．6）％，t值分别为8．615，8．661；P均〈0．01]，并且表达Siglec-1的细胞主要为单核细胞；RA组Siglec-1mRNA的相对表达量为（3．4±1．5），明显高于骨关节炎组（1．2±0.4）和健康对照组（1．0±0．4）（￡值分别为3．446，3．966；P均〈0．05）。而骨关节炎组和健康对照组之间Siglec-1蛋白和mRNA表达差异无统计学意义（P〉0．05）。此外，RA患者Siglec—1的表达与DAS28及hs-CRP均呈正相关（r值分别为0．89，0．48；P均〈0．01）。结论RA患者外周血PBMCs已经激活并高表达Siglec-1，Siglec-1可能作为无创性指标用于监测RA疾病活动度和炎症程度。

英文摘要：

Objective To investigate the expression of sialic acid-binding immunoglobulin-like lectin- 1 （Siglec-1） in the peripheral blood mononuclear cells （PBMCs） in patients with rheumatoid arthritis （RA）, osteoarthritis （OA） and healthy controls and to explore the relationship between Siglec-1 expression and disease activity in RA. Methods Siglec-1 protein and mRNA levels were measured by flow cytometry and real-time quantitative reverse transcription-polymerase chain reaction （qRT-PCR） in 42 RA patients, 28 OA patients and 26 healthy controls, respectively. The correlation studies between Siglec-1 and disease activity score 28 （DAS28） or C-reactive protein were performed. T-test was used for comparisons between groups and Pearson＇s correlation test was used for correlation analysis. Results The percentage of Siglec-1 positive ceils of PBMCs in RA group [（15.2±7.6）%] was significantly higher than that in the OA group [（2.3 ±2.6）%] or healthy controls [（2.1±1.6）%, t=-8.615, 8.661; all P〈0.01 ]. And the major cell type in PBMCs that expressed Siglec-1 was monocytes. The relative Siglec-1 mRNA expression in PBMCs in the RA group （3.4：t：1.5） was also significantly higher than that in the OA group （1.2±0.4） or healthy controls [（1.0± 0.4）, t=3.446, 3.966; all P〈0.05]. But no significant differences of Siglec-1 protein and mRNA between the OA group andhealthy controls were found. Furthermore, positive correlations between Siglec-1 protein and DAS28 or hs-CRP were found in RA patients （r--0.89, P〈0.01; r=0.48, P〈0.01）. Conclusion PBMCs are activated which are characterized by elevated expression of Siglec-I in RA patients. Circulating Siglec-1 may be considered as a potential noninvasive biomarker for monitoring disease activity in RA.