title: Autoantigenic nuclear proteins of a clinically atypical renal vasculitis.
abstract: BACKGROUND
  Systemic vasculitides constitute a heterogeneous group of diseases of autoimmunological origin characterized by inflammation of blood vessels and antibodies that react against autoantigens in a process that ultimately affects blood vessel walls. An important number of these patients present kidney disease. An endeavour of this area of research is the identification of autoantigens involved in these diseases. Accordingly, we used serum from a patient suffering from a microscopic polyangiitis, P-ANCA positive, manifesting a clinically atypical renal necrotizing glomerulonephritis and interstitial nephropathy for the identification of autoantigens; we also determined the prevalence of corresponding autoantibodies in other vasculitides, diabetic microangiopathy and in general population.
  
  
  METHODS
  The patient's serum was used as a probe for the immunoscreening method SEREX to screen a human brain cDNA expression library.
  
  
  RESULTS
  Four positive clones were isolated and sequenced. Clones Jos002 code for protein HDAC5, Jos014 for TFC4, Jos107 for RTF1, and Jos313 for POLDIP3 polymerase. The four proteins are of nuclear localization. None of them had been reported as autoantigen. Recombinant proteins were synthesised and checked as antigens by western blot with different sera from controls and patients affected with other vasculitides and diabetic microangiopathy as well. Only the serum from the patient origin of this study recognized all recombinant proteins.
  
  
  CONCLUSIONS
  We identify four nuclear proteins, HDAC5, TFC4, RTF1 and POLDIP3 polymerase as new autoantigens that could be used as markers in the diagnosis of subfamilies in immune diseases, although we cannot determine the role of these proteins in the aetiopathogenic process.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Laboratorio de Biología del Desarrollo, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Avila
authors.forename: Elisa
authors.initials: E
authors.lastname: Acosta
authors.forename: María-del-Valle
authors.initials: MD
authors.lastname: Machargo
authors.forename: María-Francisca
authors.initials: MF
authors.lastname: Arteaga
authors.forename: Eduardo
authors.initials: E
authors.lastname: Gallego
authors.forename: Haridian
authors.initials: H
authors.lastname: Cañete
authors.forename: José-Javier
authors.initials: JJ
authors.lastname: García-Pérez
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín-Vasallo