title: Clinical evaluation of cobas core anti-dsDNA EIA quant.
abstract: The measurement of antibodies to double-stranded DNA (anti-dsDNA) is a useful tool for the diagnosis and monitoring of patients with connective tissue diseases, particularly systemic lupus erythematosus (SLE). The aim of the present study was to compare a new enzyme-linked immunosorbent assay (ELISA) for the measurement of anti-dsDNA antibodies, which uses purified double-stranded plasmid DNA as the antigen (anti-dsDNA EIA Quant; Roche Diagnostics, Mannheim, Germany), with an established ELISA. The clinical usefulness of this new ELISA was also assessed. We measured anti-dsDNA antibodies in 398 serum samples that were divided into four groups: 1). routine samples sent to our laboratory for an antinuclear antibody (ANA) test (n=229), 2). samples from blood donors (n=74), 3). samples from patients with SLE (n=48), and 4) samples from patients with other autoimmune diseases (n=47). The methods used were the Cobas Core Anti-dsDNA EIA Quant (Roche Diagnostics, Mannheim, Germany) and the Anti-dsDNA test (Gull Diagnostics, Bois d'Arcy, France). We obtained a kappa index and Spearman correlation coefficient in the comparative study, and sensitivity, specificity, predictive values, and likelihood ratios in the clinical study. The results obtained show a good agreement between the two methods in both the qualitative results (kappa=0.91) and the quantitative data (r=0.854). The best accuracy, predictive values, likelihood ratios, and correlation with active disease were obtained with the Roche anti-dsDNA assay.
authors.affiliation: Servicio de Bioquímica, Laboratorio de Autoinmunidad, Hospital Universitario, Salamanca, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: González
authors.forename: Paloma
authors.initials: P
authors.lastname: Guevara
authors.forename: Belén
authors.initials: B
authors.lastname: García-Berrocal
authors.forename: José
authors.initials: J
authors.lastname: Alejandro Navajo
authors.forename: José
authors.initials: J
authors.lastname: Manuel González-Buitrago
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D004247:DNA / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D015200:Fluoroimmunoassay / Q000379:methods*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000974:Antibodies, Antinuclear; D004247:DNA