血清淀粉样蛋白A在类风湿关节炎患者体内表达的研究

Study on the expression of serum amyioid protein A in vivo in patients with rheumatoid arthritis

目的通过检测血清淀粉样蛋白A（SAA）在类风湿关节炎（RA）患者血清、关节液及滑膜中的表达，探讨其在RA发病机制中的作用。方法采用酶联免疫吸附试验（ELISA）分别检测RA、骨关节炎患者和健康对照人群血清以及RA与骨关节炎患者关节液中SAA的水平；蛋白印迹法测定SAA在血清中的表达；免疫组织化学技术检测RA和骨关节炎滑膜中SAA的表达。应用t检验或Kruska—Wallis秩和检验进行统计分析。结果RA血清中SAA含量[（318±132）μg/L]显著高于骨关节炎[（127±47）μg/L]和健康对照组[（127±41）μg／L，P均〈0．01]。RA关节液中SAA含量[（571±473）μg/L]显著高于骨关节炎[（129±33）}μg／L,t=2．46，P=0．04]。蛋白印迹法结果显示各组血清样品中均有SAA条带；RA的SAA表达明显高于其他2组。病理结果显示SAA在RA关节滑膜高表达，位于血管内皮细胞、滑膜成纤维细胞、巨噬细胞以及血管周围；在骨关节炎，SAA仅见于关节血管周围和成纤维细胞。结论RA血清和关节液中SAA的含量显著增高；SAA在RA滑膜组织中高表达，且表达位置与骨关节炎有明显差别，提示SAA可能参与了RA的炎症反应和关节损害。

Objective To investigate the role of SAA in rheumatoid arthritis （RA） pathogenesis by analyzing the expression of serum amyloid protein A（SAA） in serum, synovial fluid and synovial membrane in patients with RA. Methods SAA levels in the serum and synovial fluid in each group were detected. Sera SAA was tested by Western blotting, while the expression of SAA in RA and osteoarthritis （OA） synovium was detected by immunohistochemistry. Comparisons between groups were performed by t-tests or Kruska- Wallis test. Results The serum levels of SAA were significantly higher in RA [（318±132） μg/L] than those in OA [（127±47） μg/L] and healthy controls [（127±41） μg/L, P〈0.01]. In RA, the SAA levels in the synovial fluid [ （571±473） μg/L] were significantly higher when compared to those in OA [ （129±33） μg/L] （t=2.46,P=0.04）. Western blotting results showed that SAA bands were found in the serum samples of each group,and higher expression of SAA were seen in RA. Pathology study had showed that SAA was observed mainly in endothelial ceils, synovial fibroblasts, macrophages and perivascular areas in RA synovium. In OA, SAA was observed in perivascular areas and synovial, fibroblasts. Conclusion In RA, SAA levels in both serum and synovial fluid are significantly.higher than. those in the controls. High expression of SAA in RA synovium can be observed. Our results suggest that SAA may play a role in inflammation reaction and joint destruction of RA.