Cell lines that express membrane-associated DNA for anti-DNA antibody detection.
BACKGROUND
In this study, we evaluated the analytical reliability and clinical sensitivity of two tests (indirect immunofluorescence and ELISA) for anti-DNA antibodies which use cell membrane DNA (cmDNA) as antigen (Wil2 NS lymphoblastoid B cell line).


METHODS
We tested 97 sera of patients with systemic lupus erythematosus (SLE) and 140 control sera from healthy subjects or from patients with other systemic autoimmune diseases or infectious diseases. The results obtained with the two anti-cmDNA kits were compared with those obtained with three other methods: indirect immunofluorescence on Crithidia luciliae, ELISA anti-double-stranded DNA (anti-dsDNA) and ELISA anti-nucleosome.


RESULTS
The diagnostic sensitivity was 85% for immunofluorescence cmDNA and 90% for ELISA cmDNA, i.e., much higher than that of Crithidia (51%) and ELISA dsDNA (71%) methods, and the same as that of the ELISA nucleosome test (85%). The specificity of the cmDNA tests proved lower (92% for immunofluorescence and 87% for ELISA) than that found by anti-dsDNA Crithidia (99%), ELISA (99%) and anti-nucleosome tests (100%).


CONCLUSIONS
The results of our study indicate that cmDNA tests may be used as screening tests in patients with suspected SLE. The anti-nucleosome test offers the best diagnostic accuracy overall and can play an important role in the serological diagnosis of SLE.
Tonutti
Elio
E
Immunopatologia e Allergologia, Azienda Ospedaliero-Universitaria S. Maria della Misericordia, Udine, Italy. tonutti.elio@aoud.sanita.fvg.it
Blasone
Nadia
N
Visentini
Daniela
D
Poletto
Monica
M
Villalta
Danilo
D
Tozzoli
Renato
R
Bizzaro
Nicola
N
D000906:Antibodies / Q000737:chemistry; D000974:Antibodies, Antinuclear / Q000737:chemistry; D001774:Blood Chemical Analysis / Q000379:methods; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002624:Chemistry, Clinical / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000175:diagnosis*; D009707:Nucleosomes / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000906:Antibodies; D000974:Antibodies, Antinuclear; D009707:Nucleosomes; D004247:DNA