title: Anti-nucleosome antibodies in the diagnosis of systemic lupus erythematosus.
abstract: OBJECTIVE
  To study the prevalence and diagnostic significance of antibodies against nucleosomes in patients with systemic lupus erythematosus (SLE) as compared to five anti-nuclear antibody (ANA) assays.
  
  
  METHODS
  The study included 305 patients with SLE, 125 patients with other autoimmune rheumatic diseases, and 415 healthy controls. Anti-nucleosome antibodies were measured by an enzyme-linked immunosorbent assay (ELISA) and ANA by immunofluorescence (IF) using Hep-2 cells. Anti-double-stranded DNA (anti-dsDNA) antibodies were measured by three commercial ELISAs and by IF using Crithidia luciliae as antigen.
  
  
  RESULTS
  Compared to three ELISAs for anti-dsDNA, the anti-nucleosome assay was less sensitive (30% vs. 29-69%) but equally specific (90% vs. 77-95%) for SLE. The most sensitive test was ANA (76%), and the least sensitive was Crithidia (13%). The correlations between the different assays were good (p < 0.001 for all comparisons).
  
  
  CONCLUSIONS
  The anti-nucleosome antibody assay does not offer additional information compared to conventionally used anti-dsDNA tests in the differential diagnosis of SLE.
authors.affiliation: Department of Internal Medicine, Peijas Hospital, Vantaa, Finland. heikki.julkunen@hus.fi
authors.forename: H
authors.initials: H
authors.lastname: Julkunen
authors.forename: E M
authors.initials: EM
authors.lastname: Salonen
authors.forename: T K
authors.initials: TK
authors.lastname: Walle
authors.forename: A
authors.initials: A
authors.lastname: Miettinen
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000276:immunology; D004247:DNA / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009707:Nucleosomes / Q000276:immunology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
chemical_list: D000974:Antibodies, Antinuclear; D009707:Nucleosomes; D004247:DNA