title: Variability between methods to determine ANA, anti-dsDNA and anti-ENA autoantibodies: a collaborative study with the biomedical industry.
abstract: This study was performed by the Italian Society of Laboratory Medicine (SIMeL) in order to establish the variability between the different analytical systems currently used in clinical laboratories for the detection of autoantibodies diagnostic of systemic autoimmune disease. Sixteen industrial, and two university laboratories participated in this study which entailed the determination of anti-nuclear (ANA), anti-dsDNA and anti-ENA antibodies in 11 sera from patients with clinically diagnosed systemic rheumatic disease, using reagents produced by these companies and different methodologies (indirect immunofluorescence, immunoenzymatic assay, counterimmunolectrophoresis, immuno and western blotting). We found 93.5% agreement between the methods used for the detection of ANA, 85.2% for anti-dsDNA antibodies, and 86.9% for anti-ENA antibodies. Among the anti-ENA antibodies, regardless of the method used, detection percentages were excellent for anti-RNP and anti-SSB/La (100%), good for anti-SSA/Ro (93%), but unacceptable for the anti-Jo-1 (67%), anti-Scl70 and anti-Sm (47%) antibodies. This further stresses the need for rigorous standardisation of commercial reagents and analytical procedures, as well as the introduction of external quality assessment (EQA) programs, and a complete definition of operative protocols adjusted to the sensitivity and specificity of the various methods.
authors.affiliation: Laboratorio di Patologia Clinica, Ospedale Civile, S. Donà di Piave (VE), Italy.
authors.forename: N
authors.initials: N
authors.lastname: Bizzaro
authors.forename: R
authors.initials: R
authors.lastname: Tozzoli
authors.forename: E
authors.initials: E
authors.lastname: Tonutti
authors.forename: A
authors.initials: A
authors.lastname: Piazza
authors.forename: F
authors.initials: F
authors.lastname: Manoni
authors.forename: A
authors.initials: A
authors.lastname: Ghirardello
authors.forename: D
authors.initials: D
authors.lastname: Bassetti
authors.forename: D
authors.initials: D
authors.lastname: Villalta
authors.forename: M
authors.initials: M
authors.lastname: Pradella
authors.forename: P
authors.initials: P
authors.lastname: Rizzotti
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D015153:Blotting, Western / Q000379:methods / Q000592:standards; D003378:Counterimmunoelectrophoresis / Q000379:methods / Q000592:standards; D004247:DNA / Q000276:immunology; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D019084:Fluorescent Antibody Technique, Indirect / Q000592:standards; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards; D007159:Immunologic Tests / Q000379:methods / Q000592:standards*; D007558:Italy; D007753:Laboratories / Q000592:standards*; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D000974:Antibodies, Antinuclear; D001324:Autoantigens; C033055:anti-extractable nuclear antigen antibodies; D004247:DNA