title: ANCA are detectable in nearly all patients with active severe Wegener's granulomatosis.
abstract: BACKGROUND
  The pathogenic significance of antineutrophilic cytoplasmic antibodies (ANCA) in Wegener's granulomatosis is controversial. Their presence is influenced by the extent, severity, and activity of the disease at the time of sampling. The objective of this study was to determine the frequency of ANCA in patients with active Wegener's granulomatosis and to assess the influence of disease severity on test results.
  
  
  METHODS
  Baseline serum samples from the 180 participants in a multicentric prospective trial were tested for ANCA by indirect immunofluorescence, direct enzyme-linked immunosorbent assay (ELISA), and capture ELISA. Disease activity was measured using the Birmingham Vasculitis Activity Score for Wegener's granulomatosis. All patients had active disease at enrollment. Patients were categorized as having severe (n=128) or limited (n=52) Wegener's granulomatosis.
  
  
  RESULTS
  When all ANCA detection methods were combined, 166 patients (92%) were ANCA positive, including 96% with severe disease and 83% with limited disease.
  
  
  CONCLUSIONS
  ANCA are detectable in nearly all patients with active severe Wegener's granulomatosis, but approximately 1 of 5 patients with active limited disease are ANCA negative. Immunofluorescence and both direct and capture ELISAs are required for optimal detection, suggesting that ANCA are not recognized equally well by all testing methods.
authors.affiliation: Thoracic Disease Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic and Foundation, Rochester, Minn 55905, USA.
authors.forename: Javier D
authors.initials: JD
authors.lastname: Finkielman
authors.forename: Augustine S
authors.initials: AS
authors.lastname: Lee
authors.forename: Amber M
authors.initials: AM
authors.lastname: Hummel
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Viss
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Jacob
authors.forename: Henry A
authors.initials: HA
authors.lastname: Homburger
authors.forename: Tobias
authors.initials: T
authors.lastname: Peikert
authors.forename: Gary S
authors.initials: GS
authors.lastname: Hoffman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Merkel
authors.forename: Robert
authors.initials: R
authors.lastname: Spiera
authors.forename: E William
authors.initials: EW
authors.lastname: St Clair
authors.forename: John C
authors.initials: JC
authors.lastname: Davis
authors.forename: W Joseph
authors.initials: WJ
authors.lastname: McCune
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Tibbs
authors.forename: Steven R
authors.initials: SR
authors.lastname: Ytterberg
authors.forename: John H
authors.initials: JH
authors.lastname: Stone
authors.forename: Ulrich
authors.initials: U
authors.lastname: Specks
mesh_terms: D000328:Adult; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000097:blood / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic