title: Evidence of autoantibodies to cell membrane associated DNA (cultured lymphocytes): a new specific marker for rapid identification of systemic lupus erythematosus.
abstract: OBJECTIVE
  Autoantibodies to cell membrane associated DNA are described in systemic lupus erythematosus (SLE). The specificity of these antibodies differ from antibodies to nuclear DNA.
  
  
  METHODS
  Using indirect immunofluorescence, a specific IgG was detected giving a characteristic pattern of continuous peripheral membrane fluorescence on cultured B-lymphocytes.
  
  
  RESULTS
  This pattern was observed in 53 of 80 serum samples of SLE patients but absent in the serum samples of the control populations: 15 rheumatoid arthritis, 38 ankylosing spondylarthritis, 17 non-inflammatory osteopenic patients, and 224 blood donors. In 34 Sjögren syndrome's patients one only showed a positive test. The cmDNA specificity of these antibodies was confirmed by pattern extinction with DNAse but not RNase or protease pre-treatment of the cells. IgG to cmDNA, separated by absorption/elution from purified cmDNA immobilised on DEAE-nitrocellulose reproduced the immunofluorescence pattern pictures. Extensive serum depletion of anti-double strand or single strand DNA antibodies by absorption to cellulose bound ds- or ss-DNA affected marginally the pericellular fluorescence revealing some minor cross reactivity with nuclear DNA. Moreover, in SLE patients without detectable antibody to ds-DNA, pericellular fluorescence could be visible.
  
  
  CONCLUSIONS
  This novel rapid immunofluorescence method may serve as an identification test of SLE patients. Given its positive (97.1%) and negative (92.9%) predictive value, sensitivity (66%) and specificity (99.5%), it improves on other diagnostic tests such as the detection of antibodies to Sm.
authors.affiliation: Department of Immunology, Centres Hospitaliers Universitaires Brugmann-Huderf, Brussels, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Servais
authors.forename: M P
authors.initials: MP
authors.lastname: Guillaume
authors.forename: N
authors.initials: N
authors.lastname: Dumarey
authors.forename: J
authors.initials: J
authors.lastname: Duchateau
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000097:blood*; D000918:Antibody Specificity; D001168:Arthritis / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D002462:Cell Membrane / Q000276:immunology; D004247:DNA / Q000276:immunology*; D004277:DNA, Single-Stranded / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D000432:Methanol; D008875:Middle Aged; D016707:Tissue Fixation; D014407:Tumor Cells, Cultured
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers; D004277:DNA, Single-Stranded; D007074:Immunoglobulin G; D004247:DNA; D000432:Methanol