title: Antiphospholipase A₂ receptor autoantibodies: a comparison of three different immunoassays for the diagnosis of idiopathic membranous nephropathy.
abstract: BACKGROUND
  The recent identification of circulating autoantibodies directed towards the M-type phospholipase A2 receptor (PLA2R) has been a major advancement in the serological diagnosis of idiopathic membranous nephropathy (IMN), a common cause of nephrotic syndrome in adults. The goal of this study was to compare the performance characteristics of two commercial assays as well as the first addressable laser bead immunoassay (ALBIA) developed for the detection of anti-PLA2R antibodies.
  
  
  METHODS
  Serum samples of 157 IMN patients and 142 controls were studied. Samples were tested by a cell based immunofluorescence assay (CBA-IFA, Euroimmun, Germany), by ELISA (Euroimmun), and by a novel ALBIA employing an in vivo expressed recombinant human PLA2R.
  
  
  RESULTS
  Overall, the three assays showed significant qualitative and quantitative correlation. As revealed by receiver operating characteristic analysis, the ALBIA correlated better with the CBA-IFA than the ELISA (P = 0.0003). The clinical sensitivities/specificities for IMN were 60.0% (51.0-68.5%)/98.6% (95.0-99.8%) and 56.2% (47.2-64.8%)/100.0% (97.4-100.0%) for ALBIA and CBA-IFA, respectively.
  
  
  CONCLUSIONS
  The ALBIA represents a promising assay for the detection of anti-PLA2R antibodies showing similar performance to the CBA-IFA and the advantage of ease of use and suitability for high throughput, rapid turnaround times, and multiplexing.
authors.affiliation: Division of Nephrology, Hannover Medical School, Carl-Neuberg-straße, 30625 Hannover, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Behnert
authors.affiliation: Division of Nephrology, Hannover Medical School, Carl-Neuberg-straße, 30625 Hannover, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Schiffer
authors.affiliation: Division of Nephrology, Hannover Medical School, Carl-Neuberg-straße, 30625 Hannover, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Müller-Deile
authors.affiliation: Section of Nephrology, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Laurence H
authors.initials: LH
authors.lastname: Beck
authors.affiliation: INOVA Diagnostics, INC. 9900 Old Grove Road, San Diego, CA 32131-1638, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mahler
authors.affiliation: Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB, Canada T2N 4N1.
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
mesh_terms: D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D015433:Glomerulonephritis, Membranous / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D012372:ROC Curve; D054507:Receptors, Phospholipase A2 / Q000276:immunology*; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D001323:Autoantibodies; D054507:Receptors, Phospholipase A2