title: Anti-glomerular basement membrane antibodies in the diagnosis of Goodpasture syndrome: a comparison of different assays.
abstract: BACKGROUND
  The role of anti-glomerular basement membrane (GBM) antibodies in the pathogenesis of Goodpasture syndrome (GPS) is firmly established. Untreated, the disease may follow a fulminating course. Early identification of patients has important implications in terms of management and prognosis. Therefore, a diagnostic test for the determination of circulating anti-GBM antibodies, of very high sensitivity and specificity, is necessary. A number of assays, using different antigenic substrates, are available, but studies comparing the 'performances' of the different tests are scarce.
  
  
  METHODS
  The aim of our work was to evaluate the sensitivity and specificity of four immunoassay-based anti-GBM antibodies kits. Thirty-four serum samples from 19 GPS patients, 41 pathological and 28 normal controls were studied retrospectively (the follow-up samples were not included in the analysis of performance data). Cut-off limits were derived from receiver operating characteristics curve analysis.
  
  
  RESULTS
  All the assays showed a comparable good sensitivity (between 94.7 and 100.0%), whereas specificity varied considerably (from 90.9 to 100.0%). The better performance in terms of sensitivity/specificity was achieved by a fluorescence immunoassay which utilizes a recombinant antigen.
  
  
  CONCLUSIONS
  All the assays have a good performance, with high sensitivity; however, the specificity may vary considerably.
authors.affiliation: Unità Operativa di Immunologia Clinica, Dipartimento Area Medica, Azienda Ospedaliera Ospedale San Carlo Borromeo, Milano, Italy. renatoalberto.sinico@fastwebnet.it
authors.forename: Renato Alberto
authors.initials: RA
authors.lastname: Sinico
authors.forename: Antonella
authors.initials: A
authors.lastname: Radice
authors.forename: Caterina
authors.initials: C
authors.lastname: Corace
authors.forename: Ettore
authors.initials: E
authors.lastname: Sabadini
authors.forename: Bruna
authors.initials: B
authors.lastname: Bollini
mesh_terms: D019867:Anti-Glomerular Basement Membrane Disease / Q000175:diagnosis*; D000906:Antibodies / Q000097:blood*; D001323:Autoantibodies; D006801:Humans; D007118:Immunoassay / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D001323:Autoantibodies; C051951:antiglomerular basement membrane antibody