Anti-nucleosome antibodies in the diagnosis of systemic lupus erythematosus.
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.
Julkunen
H
H
Department of Internal Medicine, Peijas Hospital, Vantaa, Finland. heikki.julkunen@hus.fi
Salonen
E M
EM
Walle
T K
TK
Miettinen
A
A
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
D000974:Antibodies, Antinuclear; D009707:Nucleosomes; D004247:DNA