Study on the expression of serum amyloid protein A in vivo in patients with rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

ObjectiveTo 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.MethodsSAA 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 KruskaWallis test.ResultsThe serum levels of SAA were significantly higher in RA [(318±132) μg/L] than those in OA [(127±47) μg/L] and healey 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 O A [ (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 cells,synovial fibroblasts,macrophages and perivascular areas in RA synovium.In OA,SAA was observed in perivascular areas and synovial fibroblasts.ConclusionIn 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.