title: Clinical autoantibody detection by microarray.
abstract: BACKGROUND
  AMiDot is a microdot array-based immunoassay that allows simultaneous detection of multiple autoantibodies on a single patient. We evaluated the AMiDot "Systemic Autoimmune Disease" (SAD) panel, which detects antibodies to 17 different antigens.
  
  
  METHODS
  AMiDot was performed on 184 samples from blood donors and on 280 randomly selected clinical samples containing antibodies to extractable nuclear antigens or to dsDNA. The results obtained by AMiDot on the clinical samples were compared to results obtained by EliA (Thermo Fisher) for anti-Ro60, anti-La, anti-RNP, anti-Scl-70, anti-CENPB, anti-Sm, and anti-Jo-1 and by Farr assay for anti-dsDNA. Discordant results were further analyzed by immunodot (D-tek).
  
  
  RESULTS
  Concordance between AMiDot and EliA was ≥87% and κ agreement ≥0.44. When compared to EliA and immunodot (in case of discordance between AMiDot and EliA), concordance improved to ≥91% and κ agreement to ≥0.77. The sensitivity of AMiDot (compared to EliA and immunodot, in case of discordance between AMiDot and EliA) was ≥93%, except for anti-Ro60 (84%). The concordance and κ agreement of AMiDot with the Farr assay (for dsDNA antibodies) was, respectively, 84% and 0.33. The sensitivity of AMiDot for dsDNA (compared to Farr assay) was 25%. The specificity was ≥97% (in blood donors as well as in clinical samples). The within-run imprecision was 9%-27% and the between-run imprecision 29%-39%.
  
  
  CONCLUSIONS
  AMiDot offers an alternative to line immunodot assay. Individual antibody assays might suffer from low sensitivity.
authors.forename: Doreen
authors.initials: D
authors.lastname: Dillaerts
authors.forename: Heidi
authors.initials: H
authors.lastname: De Baere
authors.forename: Xavier
authors.initials: X
authors.lastname: Bossuyt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D034961:Antigens, Nuclear / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood / Q000276:immunology; D004247:DNA / Q000276:immunology; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D040081:Protein Array Analysis / Q000379:methods*; D011897:Random Allocation; D012016:Reference Values; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies; D004247:DNA