title: Antinucleosome antibodies as a marker of active proliferative lupus nephritis.
abstract: BACKGROUND
  Antinucleosome autoantibodies were previously described to be a marker of active lupus nephritis. However, the true prevalence of antinucleosome antibodies at the time of active proliferative lupus nephritis has not been well established. Therefore, the aim of this study is to define the prevalence and diagnostic value of autoantibodies against nucleosomes as a marker for active proliferative lupus nephritis.
  
  
  METHODS
  Prospective multicenter diagnostic test study.
  
  
  METHODS
  35 adult patients with systemic lupus erythematosus (SLE) at the time of the renal biopsy showing active class III or IV lupus nephritis compared with 59 control patients with SLE.
  
  
  METHODS
  Levels of antinucleosome antibodies and anti-double-stranded DNA (anti-dsDNA) antibodies.
  
  
  METHODS
  Kidney biopsy findings of class III or IV lupus nephritis at the time of sampling in a study population versus clinically inactive or no nephritis in a control population.
  
  
  RESULTS
  Increased concentrations of antinucleosome antibodies were found in 31 of 35 patients (89%) with active proliferative lupus nephritis compared with 47 of 59 control patients (80%) with SLE. No significant difference between the 2 groups with regard to number of positive patients (P = 0.2) or antibody concentrations (P = 0.2) could be found. The area under the receiver operating characteristic curve as a marker of the accuracy of the test in discriminating between proliferative lupus nephritis and inactive/no nephritis in patients with SLE was 0.581 (95% confidence interval, 0.47 to 0.70; P = 0.2). Increased concentrations of anti-dsDNA antibodies were found in 33 of 35 patients (94.3%) with active proliferative lupus nephritis compared with 49 of 58 control patients (84.5%) with SLE (P = 0.2). In patients with proliferative lupus nephritis, significantly higher titers of anti-dsDNA antibodies were detected compared with control patients with SLE (P < 0.001). The area under the receiver operating characteristic curve in discriminating between proliferative lupus nephritis and inactive/no nephritis in patients with SLE was 0.710 (95% confidence interval, 0.60 to 0.82; P < 0.001).
  
  
  CONCLUSIONS
  Antinucleosome antibodies have a high prevalence in patients with severe lupus nephritis. However, our data suggest that determining antinucleosome antibodies is of limited help in the distinction of patients with active proliferative lupus nephritis from patients with SLE without active renal disease.
authors: Clinical Immunology Laboratory, University Hospital Basel, Basel, Switzerland. cornelia.bigler@unibas.ch
authors: Cornelia
authors: C
authors: Bigler
authors: Margarita
authors: M
authors: Lopez-Trascasa
authors: Eliska
authors: E
authors: Potlukova
authors: Solange
authors: S
authors: Moll
authors: Doris
authors: D
authors: Danner
authors: Monica
authors: M
authors: Schaller
authors: Marten
authors: M
authors: Trendelenburg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004247:DNA / Q000276:immunology; D005260:Female; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009707:Nucleosomes / Q000276:immunology*; D011446:Prospective Studies
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D009707:Nucleosomes; D004247:DNA