title: Fluoroenzymeimmunoassay to detect systemic sclerosis-associated antibodies: diagnostic performance and correlation with conventional techniques.
abstract: OBJECTIVE
  Detection of systemic sclerosis-associated antibodies (SSc-Ab) in routine clinical practice is mostly restricted to anti-centromere and anti-Scl-70 antibodies. However, also other antinuclear antibodies have been shown to be valuable diagnostic and prognostic markers for the disease. The aim of this study was to evaluate the diagnostic performance of measuring the most prevalent SSc-Ab with fluoroenzymeimmunoassay (FEIA) as an alternative for the combined conventional techniques (CCT).
  
  
  METHODS
  Sera from 144 consecutive systemic sclerosis (SSc) patients previously tested by CCT (indirect immunofluorescence on HEp-2000, western blotting, protein radio immunoprecipitation and a well-documented line immunoassay) and an additional group of 266 disease controls (80 rheumatoid arthritis, 58 systemic lupus erythematosus, 50 spondyloarthropathy, 48 osteoarthritis, 18 polymyalgia rheumatica and 12 ANCA-associated vasculitis) were retrospectively evaluated. Anti-centromere-B, anti-Scl-70, anti-RNA polymerase III and anti-PM/Scl antibodies were measured using FEIA.
  
  
  RESULTS
  Using cut-off values corresponding with likelihood ratios larger than 10 FEIA obtained the following sensitivities: 45.1% for anti-centromere-B, 15.3% for anti-Scl-70, 5.6% for anti-RNA polymerase III and 2.1% for anti-PM/Scl. The overall agreement between combined conventional techniques and FEIA was good for all individual reactivities (kappa>0.800). The overall diagnostic sensitivity of 68.1% and diagnostic specificity of 98.1% were comparable to those obtained by CCT.
  
  
  CONCLUSIONS
  FEIA testing for anti-centromere-B, anti-Scl-70, anti-RNA polymerase III and anti-PM/Scl-100 shows good performance and represents an accurate alternative for the time-consuming combined conventional techniques.
authors: Department of Clinical Chemistry, Ghent University Hospital, Ghent, Belgium. carolien.bonroy@uzgent.be
authors: Carolien
authors: C
authors: Bonroy
authors: Vanessa
authors: V
authors: Smith
authors: Katleen
authors: K
authors: Van Steendam
authors: Jens
authors: J
authors: Van Praet
authors: Dieter
authors: D
authors: Deforce
authors: Katrien
authors: K
authors: Devreese
authors: Filip
authors: F
authors: De Keyser
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D051936:Centromere Protein B / Q000276:immunology; D004264:DNA Topoisomerases, Type I; D005095:Exoribonucleases / Q000276:immunology; D063326:Exosome Multienzyme Ribonuclease Complex / Q000276:immunology; D019084:Fluorescent Antibody Technique, Indirect; D015200:Fluoroimmunoassay; D006801:Humans; D007124:Immunoenzyme Techniques; D009687:Nuclear Proteins / Q000276:immunology; D011237:Predictive Value of Tests; D012320:RNA Polymerase III / Q000276:immunology; D015531:Radioimmunoprecipitation Assay; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000974:Antibodies, Antinuclear; D001324:Autoantigens; D015415:Biomarkers; C497926:CENPB protein, human; D051936:Centromere Protein B; D009687:Nuclear Proteins; C048100:Scl 70 antigen, human; D012320:RNA Polymerase III; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C077044:EXOSC10 protein, human; D004264:DNA Topoisomerases, Type I