title: Incidence, target antigens, and clinical implications of antineutrophil cytoplasmic antibodies in rheumatoid arthritis.
abstract: OBJECTIVE
  To determine the incidence of antineutrophil cytoplasmic antibodies (ANCA) in rheumatoid arthritis (RA), to detect the target antigens of ANCA, and to compare clinical and laboratory data of ANCA+ with ANCA- patients with RA.
  
  
  METHODS
  385 sera of patients with RA were screened for ANCA by indirect immunofluorescence. ANCA+ sera were further analyzed for target antigens by ELISA: The ANCA+ patients were compared to randomly selected ANCA- patients with RA with respect to serological and radiological variables and extraarticular involvement.
  
  
  RESULTS
  ANCA were found in 16% of patients with RA (61/385 sera). All sera showed a perinuclear (pANCA) pattern. Antibodies directed against proteinase 3 were not observed. The analysis of ANCA+ and ANCA- patients revealed that the pANCA+ group exhibited significantly higher serological markers of inflammation (p < 0.005) and a higher incidence of rheumatoid factor (p < 0.005). Furthermore, vasculitic involvement was found at a higher frequency (p < 0.05) in the pANCA+ group. Five patients in the pANCA+ group had pulmonary involvement, but none in the pANCA- group.
  
  
  CONCLUSIONS
  pANCA in RA may be a marker for a more aggressive course of disease in respect to serological variables and extraarticular manifestations including rheumatoid vasculitis and lung involvement.
authors.affiliation: Poliklinik für Rheumatologie, Universität Lübeck, Germany.
authors.forename: M G
authors.initials: MG
authors.lastname: Braun
authors.forename: E
authors.initials: E
authors.lastname: Csernok
authors.forename: W H
authors.initials: WH
authors.lastname: Schmitt
authors.forename: W L
authors.initials: WL
authors.lastname: Gross
mesh_terms: D000368:Aged; D000937:Antigen-Antibody Reactions / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology*; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D011859:Radiography; D012698:Serologic Tests; D014657:Vasculitis / Q000175:diagnosis / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015415:Biomarkers