title: The anti-mutated citrullinated vimentin response classifies patients with rheumatoid arthritis into broad and narrow responders.
abstract: OBJECTIVE
  Autoantibodies against citrullinated peptide antigens (ACPA) are routinely determined to diagnose rheumatoid arthritis (RA) and are predictive of a more severe course of the disease. We here set out to address an involvement of ACPA in the pathogenesis of RA and investigated the recognition pattern of antibodies against 2 citrullinated antigens in more detail.
  
  
  METHODS
  The sera of 77 patients fulfilling the American College of Rheumatology criteria for RA were analyzed for subclass titers of anti-mutated citrullinated vimentin (MCV) and anticyclic citrullinated peptide (CCP) antibodies by combining subclass specific detection antibodies with commercially available CCP and MCV ELISA plates. Cross-reactivities between anti-MCV and anti-CCP antibodies were detected using a sequential ELISA system.
  
  
  RESULTS
  IgG1, IgG3, and IgG4 titers among anti-MCV and anti-CCP antibodies correlated significantly. Cross-reactivity of MCV-specific antibodies against CCP could be detected in 8 of 16 patients' sera; however, cross-binding of MCV-specific IgG4 was weaker compared to total IgG.
  
  
  CONCLUSIONS
  The inherent capacity of IgG4 to exchange F(ab) arms provides insight into the anti-MCV antibody diversity and suggests a classification of ACPA positive patients into broad and narrow responders.
authors.affiliation: Institute of Immunology, University of Rostock, Germany. robby.engelmann@med.uni-rostock.de
authors.forename: Robby
authors.initials: R
authors.lastname: Engelmann
authors.forename: Jan
authors.initials: J
authors.lastname: Brandt
authors.forename: Martin
authors.initials: M
authors.lastname: Eggert
authors.forename: Kirsten
authors.initials: K
authors.lastname: Karberg
authors.forename: Andreas
authors.initials: A
authors.lastname: Krause
authors.forename: Gunther
authors.initials: G
authors.lastname: Neeck
authors.forename: Brigitte
authors.initials: B
authors.lastname: Mueller-Hilke
mesh_terms: D000918:Antibody Specificity; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D010456:Peptides, Cyclic / Q000276:immunology*; D014746:Vimentin / Q000737:chemistry / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; D010456:Peptides, Cyclic; D014746:Vimentin; C487763:cyclic citrullinated peptide