title: Rapid detection of autoantibodies to dsDNA with the particle gel immunoassay (ID-PaGIA).
abstract: OBJECTIVE
  To describe a new particle agglutination test for the detection of autoantibodies to double stranded DNA (dsDNA).
  
  
  METHODS
  Serum samples were collected from 40 unselected healthy blood donors and 200 patients with systemic lupus erythematosus (SLE) or a positive antinuclear antibody screen, or both. The samples were tested in the presence of red high density polystyrene particles coated with purified human dsDNA using the gel technique (Micro Typing System, ID-PaGIA, particle gel immunoassay). The results were compared with those obtained by the two standard anti-dsDNA antibody detection methods, Crithidia luciliae immunofluorescence test (CLIF) and enzyme linked immunosorbent assay (ELISA).
  
  
  RESULTS
  The three anti-dsDNA assays exhibited an overall agreement of 87% and significant correlation with each other (p<0.0001). In the SLE group (n=71), 45 patients (63%) were found to be positive by ID-PaGIA compared with only 11/129 (9%) patients in the non-SLE group. Thus the ID-PaGIA had a sensitivity of 63%, and a specificity of 92% for SLE. In comparison, the standard detection methods showed sensitivities of 62% (CLIF) and 70% (ELISA) and specificities of 99% (CLIF) and 84% (ELISA) for SLE. Anti-dsDNA reactivity in the agglutination assay correlated closely with the quantities of antibody obtained by CLIF (r=0.81, p<0.0001) and ELISA (r=0.73, p<0.0001).
  
  
  CONCLUSIONS
  The new particle gel agglutination test is a sensitive and specific immunoassay. It is a simple test procedure that might be well suited as a rapid screening method.
authors.affiliation: Institute of Transfusion Medicine, Charité University Hospital/Virchow Clinic, Humboldt University Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Seltsam
authors.forename: P
authors.initials: P
authors.lastname: Schwind
authors.forename: K
authors.initials: K
authors.lastname: Abraham
authors.forename: F
authors.initials: F
authors.lastname: Hiepe
authors.forename: S
authors.initials: S
authors.lastname: Cygan
authors.forename: I
authors.initials: I
authors.lastname: Aebischer
authors.forename: A
authors.initials: A
authors.lastname: Salama
mesh_terms: D000372:Agglutination Tests / Q000379:methods; D000974:Antibodies, Antinuclear / Q000032:analysis*; D002850:Chromatography, Gel / Q000379:methods / Q000592:standards; D004247:DNA / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards*; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000276:immunology; D008863:Microspheres; D012680:Sensitivity and Specificity
chemical_list: D000974:Antibodies, Antinuclear; D004247:DNA