title: Interlaboratory variability of the antiperinuclear factor (APF) test for rheumatoid arthritis.
abstract: The antiperinuclear factor (APF) test is as sensitive and specific for rheumatoid arthritis as the classical rheumatoid factor tests. Five European laboratories decided to perform a consensus study on the interlaboratory variability of the APF test. They used different donor cells, different conjugates and different criteria for positivity. However, the results differed by not more than one two-fold dilution step, when expressed in international units using WHO reference rheumatoid arthritis serum as the standard.
authors.affiliation: Department of Autoimmune Diseases, Central Laboratory of the Bloodtransfusion Service, Amsterdam, The Netherlands.
authors.forename: T E
authors.initials: TE
authors.lastname: Feltkamp
authors.forename: J M
authors.initials: JM
authors.lastname: Berthelot
authors.forename: A M
authors.initials: AM
authors.lastname: Boerbooms
authors.forename: H G
authors.initials: HG
authors.lastname: Geertzen
authors.forename: R
authors.initials: R
authors.lastname: Hoet
authors.forename: F
authors.initials: F
authors.lastname: De Keyser
authors.forename: W J
authors.initials: WJ
authors.lastname: van Venrooij
authors.forename: G
authors.initials: G
authors.lastname: Verbruggen
authors.forename: E M
authors.initials: EM
authors.lastname: Veys
authors.forename: P
authors.initials: P
authors.lastname: Youinou
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D019411:Clinical Laboratory Techniques / Q000592:standards*; D003245:Consensus Statements as Topic; D005060:Europe / Q000453:epidemiology; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D014944:World Health Organization
chemical_list: D000974:Antibodies, Antinuclear; C030902:antiperinuclear factor