Elena Csernok1, Jan Damoiseaux2, Niels Rasmussen3, Bernhard Hellmich1, Pieter van Paassen4, Pieter Vermeersch5, Daniel Blockmans6, Jan-Willem Cohen Tervaert7, Xavier Bossuyt8. 1. Department of Internal Medicine, Rheumatology and Immunology, Vasculitis Center Tübingen-Kirchheim, University Hospital Kirchheim, Germany. 2. Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands. 3. Department of Autoimmune Serology, Statens Serum Institute, Copenhagen, Denmark. 4. Department of Internal Medicine, Section of Nephrology and Immunology, Maastricht University Medical Center, Maastricht, The Netherlands. 5. Clinical Department of Laboratory Medicine, University Hospitals Leuven, 3000 Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium. 6. Clinical Department of General Internal Medicine, Research Department of Microbiology and Immunology, Laboratory of Clinical Infectious and Inflammatory Disorders, University Hospitals Leuven, Leuven, Belgium. 7. Maastricht University, The Netherlands. 8. Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium. Electronic address: Xavier.Bossuyt@uzleuven.be.
Abstract
OBJECTIVES: The aim of this multicenter EUVAS study was to evaluate the diagnostic performance of multi-parametric indirect immunofluorescence (IIF) assays to detect anti-neutrophil cytoplasmic antibodies (ANCA) in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). PATIENTS AND METHODS: The study included 912 samples from diseased controls and 249 diagnostic samples from GPA (n=183) and MPA (n=66) patients. The performance of two automated multi-parametric assays [Aklides (Medipan/Generic Assays) and EuroPattern (Euroimmun)] combining IIF on cellular and purified antigen substrates was compared with two manual IIF analyses and with commercially available ELISAs for MPO- and PR3-ANCA (Euroimmun). RESULTS: The area under the curve (AUC) of the receiver operating characteristics (ROC) curve to discriminate AAV from controls was 0.925, 0.848, 0.855 and 0.904 for, respectively, the two manual analyses, Aklides and EuroPattern, and 0.959, 0.921 and 0.886 for, respectively, antigen-specific ELISA, antigen-coated beads, and microdot, respectively. Variation in pattern assignment between IIF methods was observed. CONCLUSION: The performance of IIF depends on the substrate used and the definition of IIF patterns. The performance of automated IIF is improved by multi-parameter testing (combined IIF and antigen-specific testing). Given the variability between IIF methods, the diagnostic importance of this technique is questioned.
OBJECTIVES: The aim of this multicenter EUVAS study was to evaluate the diagnostic performance of multi-parametric indirect immunofluorescence (IIF) assays to detect anti-neutrophil cytoplasmic antibodies (ANCA) in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). PATIENTS AND METHODS: The study included 912 samples from diseased controls and 249 diagnostic samples from GPA (n=183) and MPA (n=66) patients. The performance of two automated multi-parametric assays [Aklides (Medipan/Generic Assays) and EuroPattern (Euroimmun)] combining IIF on cellular and purified antigen substrates was compared with two manual IIF analyses and with commercially available ELISAs for MPO- and PR3-ANCA (Euroimmun). RESULTS: The area under the curve (AUC) of the receiver operating characteristics (ROC) curve to discriminate AAV from controls was 0.925, 0.848, 0.855 and 0.904 for, respectively, the two manual analyses, Aklides and EuroPattern, and 0.959, 0.921 and 0.886 for, respectively, antigen-specific ELISA, antigen-coated beads, and microdot, respectively. Variation in pattern assignment between IIF methods was observed. CONCLUSION: The performance of IIF depends on the substrate used and the definition of IIF patterns. The performance of automated IIF is improved by multi-parameter testing (combined IIF and antigen-specific testing). Given the variability between IIF methods, the diagnostic importance of this technique is questioned.
Authors: Allyson C Egan; Andreas Kronbichler; Irmgard Neumann; Alessandra Bettiol; Nicholas Carlson; Maria C Cid; Giacomo Emmi; Seerapani Gopaluni; Lorraine Harper; Thomas Hauser; Mark A Little; Raashid A Luqmani; Alfred Mahr; Mark McClure; Aladdin J Mohammad; Karl Emil Nelveg-Kristensen; Sophie Ohlsson; Chen Au Peh; Matthew Rutherford; Beatriz Sanchez Alamo; Jennifer Scott; Mårten Segelmark; Rona M Smith; Wladimir M Szpirt; Gunnar Tomasson; Giorgio Trivioli; Augusto Vaglio; Michael Walsh; Maria Wester Trejo; Kerstin Westman; Ingeborg M Bajema; David R W Jayne Journal: Kidney Int Rep Date: 2022-05-25
Authors: Ingeborg M Bajema; Jan A Bruijn; Alina Casian; Maria C Cid; Elena Csernok; Emma van Daalen; Lorraine Harper; Thomas Hauser; Mark A Little; Raashid A Luqmani; Alfred Mahr; Cristina Ponte; Alan Salama; Mårten Segelmark; Kazuo Suzuki; Jan Sznajd; Y K Onno Teng; Augusto Vaglio; Kerstin Westman; David Jayne Journal: Kidney Int Rep Date: 2017-09-21