title: Clinical performance evaluation of a novel rapid response chemiluminescent immunoassay for the detection of autoantibodies to extractable nuclear antigens.
abstract: BACKGROUND
  We analyzed the performance of a novel ENA screening chemiluminescent immunoassay (CIA) and the confirmation QUANTA Flash tests.
  
  
  METHODS
  Sera (n=1079) from patients referred to a rheumatology clinic were screened by QUANTA Flash ENA7 (INOVA Diagnostics). All positive (n=89) and a matched control group (n=90) were reflexed for autoantibodies to the individual antigens. Moreover, sera from patients with systemic lupus erythematosus (SLE, n=252), systemic sclerosis (SSc, n=64), polymyositis/dermatomyositis (PM/DM, n=72), Sjögren's syndrome (SjS, n=39) as well as disease controls (n=605) were tested by ENA7 CIA and by Quanta Lite ENA6 ELISA (INOVA).
  
  
  RESULTS
  89/1079 (8.3%) samples were ENA7 CIA positive with the following reactivity profile: RNP (36.0%), Sm (13.5%), Scl-70 (9.0%), Jo-1 (0.0%), Ro60 (44.9%), Ro52 (39.3%) and SS-B (24.7%). In the negative group, the reactivity profile was: RNP (1.1%), Sm (1.1%), Scl-70 (2.2%) and 0.0% for Jo-1, Ro60, Ro52 and SS-B. The positive/negative/total agreements (ENA7 CIA vs. confirmation assays) were 95.3%/91.5%/93.3%. The sensitivity of the ENA7 CIA was 62.3% in SLE, 54.7% in SSc, 92.3% in SjS, 50.0% in PM/DM, and 61.8% in the total systemic autoimmune rheumatic disease (SARD) population (specificity 95.0%).
  
  
  CONCLUSIONS
  The QUANTA Flash ENA7 CIA is a reliable screening test.
authors.affiliation: INOVA Diagnostics, Inc., San Diego, CA, United States.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Bentow
authors.forename: Andreas
authors.initials: A
authors.lastname: Swart
authors.forename: Jason
authors.initials: J
authors.lastname: Wu
authors.forename: Andrea
authors.initials: A
authors.lastname: Seaman
authors.forename: Mariangela
authors.initials: M
authors.lastname: Manfredi
authors.forename: Maria
authors.initials: M
authors.lastname: Infantino
authors.forename: Maurizio
authors.initials: M
authors.lastname: Benucci
authors.forename: Gabriella
authors.initials: G
authors.lastname: Lakos
authors.forename: Michael
authors.initials: M
authors.lastname: Mahler
mesh_terms: D034961:Antigens, Nuclear / Q000097:blood* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D003882:Dermatomyositis / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007118:Immunoassay; D008163:Luminescent Measurements; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000175:diagnosis*; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000097:blood / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D012859:Sjogren's Syndrome / Q000097:blood / Q000175:diagnosis*
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies
keywords: ALBIA; AMR; Autoantibodies; CIA; CLSI; CTD; Clinical and Laboratory Standards Institute; Connective tissue disease; ELISA; ENA; LIA; PBC; PM/DM; SARD; SLE; SSc; SjS; Sjögren's syndrome; Systemic lupus erythematosus; addressable laser bead assays; analytical measuring range; chemiluminescent immunoassay; connective tissue disease; line immunoassays; polymyositis/dermatomyositis; primary biliary cirrhosis; systemic autoimmune rheumatic disease; systemic lupus erythematosus; systemic sclerosis