ABSTRACT
BACKGROUND: Rheumatoid factor (RF) is a kind of autoantibody which is routinely used as a factor in patients with rheumatoid arthritis (RA) to evaluate disease activity and severity.But in clinical practice, it occurs frequently that RF values do not decrease according to clinical improvement in RA patients. OBJECTIVE: To investigate the association between rheumatoid factor (RF) and activity or disease severity of RA.DESIGN, TIME AND SETTING: A randomized cross-sectional study was performed in the Department of Rheumatology and Immunology, the Third Affiliated Hospital of Sun Yat-sen University during September 2006 and September 2007.PARTICIPANTS: Seventy-six patients,65 females and 11 males,mean age of (44±13) years,with RA diagnosed according to the American College of Rheumatology (ACR) criteria for RA were included in this study. METHODS: Seventy-six patients with active RA were randomly recruited and assessed for functional status,radiographic change,joint pain,morning stiffness, tender joint count (TJC), tender joint score (TJS), swollen joint count (SJC), swollen joint score (SJS), Health Assessment Questionnaire (HAQ), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP),RF,and hemoglobin. The method of Pearson correlation or Spearman rank correlation was performed for assessing the association between RF and these indices separately, normally distributed data for Pearson correlation, nonnormally distributed data for Spearman rank correlation. MAIN OUTCOME MEASURES: Correlation of RF with above mentioned factors. RESULTS: None of the correlation coefficients between RF and indices including age,disease duration, functional status,radiographic change,joint pain, morning stiffness, TJC,TJS,SJC,SJS,HAQ,ESR,CRP,hemoglobin were significant (P＞0.05). CONCLUSION: No associations between RF and activity or severity of RA are studied.