Abstract: [Abstract] Objective To investigate the correlation between serum amyloid A and disease activity (DAS28) in patients with rheumatoid arthritis (RA). Methods 44 patients with RA, 35 patients with systemic lupus erythematosus (SLE), 18 patients with osteoarthritis (OA) and 30 healthy people were enrolled in this study. Serum levels of SAA were measured by ELISA. Erythrocyte sedimentation rate (ESR) was measured by the Westergren method. Serum C reactive protein (CRP) concentration was examined by immunonephelometry assay. The correlations between SAA and DAS28、ESR and CRP were assessed, respectively. Results In RA patients, serum levels of SAA was significantly higher (P<0.05) than that in SLE、OA and healthy controls. ESR and CRP levels were both markedly higher than OA and healthy controls, but had no significant difference with SLE. SAA、ESR and CRP levels in serum all had positive correlations with DAS28（r=0.790，P<0.001；r=0.679, P<0.001；r=0.431, P=0.004）. Conclusion Serum SAA levels in RA patients were higher than those in controls and had a positive correlation with RA disease activity, which was more sensitive than ESR and CRP, suggesting that SAA can be a new serological indicator to assess disease activity in RA.

Key words: rheumatoid arthritis, Serum Amyloid A, disease activity, Erythrocyte sedimentation rate, C reactive protein