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).Conclusion: The anti‐nucleosome antibody assay does not offer additional inf...