title: [Diagnostic significance of combined detection of rheumatoid factor and anticyclic citrullinated peptide antibodies in rheumatoid arthritis].
abstract: OBJECTIVE
  To evaluate the significance of the combination of rheumatoid factor (RF) and anti-filaggrin antibodies (AFAs) in the diagnosis of rheumatoid arthritis (RA).
  
  
  METHODS
  Sera from 266 RA patients and 186 controls were studied. RF and some kinds of AFAs (including antikeratin antibodies, anti-perinuclear factor and anticyclic citrullinated peptide antibodies) were detected using immunofluorescence and ELISA respectively. The distributions of these antibodies were compared to determine the significance of the combination of RF and AFAs.
  
  
  RESULTS
  The sensitivity and secificity of RF for the diagnosis of RA were 65.8% and 81.8% respectively, as compared with those of anti-CCP or RF positive were 86.5% and 80.6% respectively. Only a slight change was found in the secificity and negative predictive value between them. RF could not be detected in 91 patients while 64.8% of them could be found to have at least one kind of AFAs.
  
  
  CONCLUSIONS
  AFAs, particular anticyclic citrullinated peptide antibodies, could be helpful for the diagnosis of RA especially in RF-negative patients.
authors.affiliation: Department of Rheumatology and Immunology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Mu
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Sun
authors.forename: Zhan-guo
authors.initials: ZG
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis*; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D012217:Rheumatoid Factor / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor