title: Diagnostic accuracy of the FIDIS multiplex fluorescent microsphere immunodetection system for anti-extractable nuclear antigen (ENA) antibodies in connective tissue diseases.
abstract: BACKGROUND
  Anti-extractable nuclear antigen antibodies (ENA) are markers of connective tissue diseases (CTDs).
  
  
  METHODS
  We compared FIDIS reagents in the multiplex fluorescent microsphere immunodetection system to INNO-LIA and immunodiffusion for 174 antinuclear antibody-positive patients, 102 with well-defined CTDs and 72 disease controls.
  
  
  RESULTS
  No significant differences were found in sensitivity or specificity between FIDIS and immunodiffusion, or between FIDIS and INNO-LIA for all anti-ENA in all CTD patients; nor were any differences found for individual anti-ENAs within distinct CTDs. The FIDIS sensitivity was 41% (anti-SSA) and 17% (anti-SSB) in lupus erythematosus (LE) or primary Sjögren's syndrome; 5% (anti-ribosome and anti-Sm) in LE; 17% (anti-RNP) in LE or mixed CTD; 21% (anti-Scl70) in systemic sclerosis; and 61% (anti-centromere) in limited systemic sclerosis. The specificity reached 88%-100%. Receiver operating characteristic curve areas did not differ between FIDIS and INNO-LIA. Agreement ranged from 91% (anti-SSB) to 99% (anti-Jo1) between FIDIS and INNO-LIA, and from 95% (anti-Scl70) to 100% (anti-Sm) between FIDIS and immunodiffusion. Samples scored positive with all techniques in 83% (anti-centromere), 70% (anti-RNP), 67% (anti-Jo1), 60% (anti-SSA), 40% (anti-SSB), 33% (anti-ribosome), 25% (anti-Sm) and 13% (anti-Scl70) of cases.
  
  
  CONCLUSIONS
  The diagnostic performance of FIDIS anti-ENA reagents is comparable to immunodiffusion and INNO-LIA.
authors: Laboratory of Hematology, Academisch Ziekenhuis Vrije Universiteit Brussel, Brussels, Belgium. martine.vercammen@az.vub.ac.be
authors: Martine
authors: M
authors: Vercammen
authors: Patricia
authors: P
authors: Meirlaen
authors: Jacques
authors: J
authors: Sennesael
authors: Brigitte
authors: B
authors: Velkeniers
authors: Sara
authors: S
authors: T'Kint
authors: Leon
authors: L
authors: Verbruggen
authors: Patrick
authors: P
authors: Haentjens
authors: Linda
authors: L
authors: Broodtaerts
authors: Christian
authors: C
authors: Demanet
authors: Marc
authors: M
authors: De Waele
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear / Q000097:blood*; D002648:Child; D003240:Connective Tissue Diseases / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D034961:Antigens, Nuclear