title: Anti-telomere antibodies in systemic lupus erythematosus (SLE): a comparison with five antinuclear antibody assays in 430 patients with SLE and other rheumatic diseases.
abstract: OBJECTIVE
  To investigate the prevalence and diagnostic significance of antibodies against telomeric DNA in systemic lupus erythematosus (SLE) and other autoimmune rheumatic diseases, and to make comparisons with five conventional anti-DNA or anti-nuclear antibody (ANA) assays.
  
  
  METHODS
  Antibodies to telomeres, which are highly repetitive sequences of DNA (TTAGGG/CCCTAA) at the end of eukaryotic chromosomes, were measured by an enzyme linked immunosorbent assay (ELISA) in 305 patients with SLE and 125 patients with other autoimmune rheumatic diseases (78 rheumatoid arthritis, 32 primary Sjögren's syndrome, eight mixed connective tissue disease, seven miscellaneous rheumatic diseases). Other assays used were two commercial ELISA assays for anti-dsDNA using calf thymus as antigen, Crithidialuciliae immunofluorescence, and radioimmunoassay (RIA) for anti-dsDNA and immunofluorescence using Hep-2 cells for ANA.
  
  
  RESULTS
  The prevalence of anti-telomere in SLE was 60%, v 5% in rheumatoid arthritis and 18% in other autoimmune rheumatic diseases. Specificity of anti-telomere for SLE was 91%; positive and negative predictive values were 95% and 46%, respectively. For anti-dsDNA by two ELISA assays using calf thymus as antigen, sensitivities were 69% and 29% and specificities 66% and 96%, respectively. Other anti-dsDNA assays had low sensitivities (RIA 43%, Crithidia immunofluorescence 13%). The association of anti-telomere with a history of nephritis in patients with SLE was stronger (p = 0.005) than by any other assay (p = 0.006-0.999). The correlations between the different assays were good (p<0.001 for all comparisons).
  
  
  CONCLUSIONS
  The new ELISA for anti-telomere antibodies using standardised human dsDNA as antigen is a sensitive and highly specific test for SLE.
authors.affiliation: Peijas Hospital, 01400 Vantaa, Finland.
authors.forename: E M
authors.initials: EM
authors.lastname: Salonen
authors.forename: A
authors.initials: A
authors.lastname: Miettinen
authors.forename: T K
authors.initials: TK
authors.lastname: Walle
authors.forename: S
authors.initials: S
authors.lastname: Koskenmies
authors.forename: J
authors.initials: J
authors.lastname: Kere
authors.forename: H
authors.initials: H
authors.lastname: Julkunen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology; D008181:Lupus Nephritis / Q000175:diagnosis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012216:Rheumatic Diseases / Q000175:diagnosis / Q000276:immunology; D012680:Sensitivity and Specificity; D016615:Telomere / Q000276:immunology*
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers