Abstract: Objective To investigate the expression patterns of neutrophil gelatinase-associated lipocalin （NGAL） in sera and synovial fluids of rheumatoid arthritis（RA）patients. Method We collected blood and synovial fluid samples from 60 RA patients and 60 normal persons as control in Xinjiang Peoples'Hospital. The RA patients were divided into two groups by DAS28 scores. Synovial fluid samples were collected from RA patients,and NGAL was detected by latex particle-enhanced turbidimetric immunoassay. Results The serum NGAL levels were （375.3±166.4） μg/L in RA patients,（512.1±128.7） μg/L in the patients with activity phase,（239.2±43.5） μg/L in those with alleviated phase,and （70.9±10.1） μg/L in control group. The NGAL level was significantly higher in the patients than that in the control,and statistically higher in the patients of activity phase than those of alleviated victims. The NGAL level was also correlated with increased inflammation cytokines such as TNF-α,IL-6 and CRP in RA patients. Additionally,pNGAL production was positively correlated with sfNGAL level in RA patients. Conclusion NGAL showed a distinct difference between RA patients and normal individuals and NGAL expression has a close correlation with the disease activity,suggesting that NGAL could be a potential marker for the diagnosis and therapy management of rheumatoid arthritis.

Key words: Rheumatic arthritis, Neutrophil gelatinase-associated lipocalin, NGAL2, Autoimmunity