title: Comparison of antinuclear antibody testing methods: immunofluorescence assay versus enzyme immunoassay.
abstract: Performances of anti-nuclear antibody testing by immunofluorescence assay (ANA-IFA) and enzyme immunoassay (ANA-EIA) were compared in relation to patient diagnosis. A total of 467 patient serum samples were tested by ANA-IFA (Kallestad; Sanofi) and ANA-EIA (RADIAS; Bio-Rad), and their age, sex, diagnosis, disease status, and medications were obtained through chart review. Reference ranges were established by testing 98 healthy blood donor samples. Eighty-six samples came from patients with diffuse connective tissue diseases, including systemic lupus erythematosus, discoid lupus erythematosus, or drug-induced lupus (n = 71); systemic sclerosis, CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal motility abnormalities, sclerodactyly, and telangiectasia), or Raynaud's syndrome (n = 8); Sjögren's syndrome (n = 5); mixed connective tissue disease (n = 5); and polymyositis or dermatomyositis (n = 3). The sensitivity, specificity, positive predictive value, and negative predictive value for ANA-IFA were 87.2, 48.0, 29.1, and 93.9%, respectively, for the reference range of < 1:160. For ANA-EIA, they were 90.7, 60.2, 35.8, and 96.4%, respectively, for the reference range of < 0.9. ANA-EIA offers equivalent sensitivity and higher specificity compared to ANA-IFA.
authors.affiliation: Bio-Rad Laboratories, Hercules, California 94547, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Gniewek
authors.forename: D P
authors.initials: DP
authors.lastname: Stites
authors.forename: T M
authors.initials: TM
authors.lastname: McHugh
authors.forename: J F
authors.initials: JF
authors.lastname: Hilton
authors.forename: M
authors.initials: M
authors.lastname: Nakagawa
mesh_terms: D000974:Antibodies, Antinuclear / Q000032:analysis* / Q000097:blood; D003240:Connective Tissue Diseases / Q000175:diagnosis / Q000276:immunology; D005069:Evaluation Studies as Topic; D005455:Fluorescent Antibody Technique / Q000706:statistics & numerical data; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D012016:Reference Values; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000974:Antibodies, Antinuclear