The diagnostic value of antibodies in synovial fluid for rheumatoid arthritis / 中华风湿病学杂志

ABSTRACT

Objective To study the concentration of anti-cyclic citrullinated peptide antibody (CCP),rheumatoid factor (RF),immunoglobulin (Ig) in synovial fluid and serum of patients with rheumatoid arthritis (RA),and the positive rate of anti-keratin antibodies (AKA) and anti-perinuclear factor (APF) were also measured.The aim was to explore the diagnostic value of these antibodies in synovial fluid for RA.Methods Thirty RA patients were collected,synovial fluid were withdrawn from the inflamed joints and peripheral blood were collected at the same time.Anti-CCP antibody,AKA,APF and RF were measured.The cut-off value of CCP in synovial fluid was determined through operating characteristic curve (ROC curves) analysis.The antibody levels in serum and synovial fluid were compared.Statistical analyses were performed using t test,and Pearson's correlation test.Results The cutoff value of CCP in RA synovial was higher,which was 29.00 U/ml,with the sensitivity of 87.00％ and specificity of 94.10％.There were significant differences in the concentration among anti-CCP antibody [(326±313) U/ml,(496±454) U/ml,t=-2.399,P＜0.05],IgG [(57±39) mg/L,(173±86) mg/L,t=-7.4792,P＜0.05),RF [(53±36) U/ml,(149±104) U/ml,t=-2.402,P＜0.05] in synovial and blood serum respectively in RA patients.Conchsion The diagnosis of RA is enhanced if anti-CCP antibodies,RF and IgG in synovial fluid are examined.They are supplementary to RA diagnosis and are helpful for clinical practice,especially for patient with very recent-onset RA.