title: Screening of antinuclear antibodies: comparison between enzyme immunoassay based on nuclear homogenates, purified or recombinant antigens and immunofluorescence assay.
abstract: Current clinical practice considers antinuclear antibody (ANA) testing as a screening test; this has a major impact on laboratory work with a growing volume of analyses that need to be performed rapidly, to maintain good specificity and sensitivity. Ongoing discussions have been raised in order to identify the best technology to use in ANA screening, taking into account both clinical and economical implications. The aim of our study was to compare three different enzyme immunoassays (EIA) with immunofluorescence (IF) assay in order to identify which test is better for use as a screening test. The study was performed on 473 sera and the three different EIA tests were based on nuclear homogenates from HeLa cells, purified antigens from HEp-2 cells and recombinant antigens, respectively. The concordance between EIA-ANA and IF-ANA techniques, determined by the K statistic, was acceptable, but not complete, and discrepancies between both EIA-positive/IF-negative samples and IF-positive/EIA-negative were found. Both methods show interesting diagnostic abilities, however, the IF-ANA assay seems to be the first choice test in a well-standardized immunofluorescence laboratory with experienced microscopists, whereas the EIA test might be useful especially in large-scale ANA screening.
authors.affiliation: Department of Internal Medicine and Department of Laboratory Medicine-PTV, University of Rome Tor Vergata, Rome, Italy. Bernardini@Med.UniRoma2.it
authors.forename: Sergio
authors.initials: S
authors.lastname: Bernardini
authors.forename: Maria
authors.initials: M
authors.lastname: Infantino
authors.forename: Lorenza
authors.initials: L
authors.lastname: Bellincampi
authors.forename: Marzia
authors.initials: M
authors.lastname: Nuccetelli
authors.forename: Antonella
authors.initials: A
authors.lastname: Afeltra
authors.forename: Roberta
authors.initials: R
authors.lastname: Lori
authors.forename: Antonino
authors.initials: A
authors.lastname: Biroccio
authors.forename: Andrea
authors.initials: A
authors.lastname: Urbani
authors.forename: Giorgio
authors.initials: G
authors.lastname: Federici
mesh_terms: D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood*; D000918:Antibody Specificity; D019411:Clinical Laboratory Techniques; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004847:Epithelial Cells; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D008403:Mass Screening; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D000974:Antibodies, Antinuclear; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins