title: Autoantibodies to the nucleolar organizer antigen NOR-90 in children with systemic rheumatic diseases.
abstract: OBJECTIVE
  To determine the frequency of autoantibodies directed against the nucleolar organizer antigen NOR-90 [human upstream binding factor (hUBF)] in pediatric patients with systemic rheumatic diseases. Two children with antibodies to NOR-90 are reported.
  
  
  METHODS
  Two hundred thirty-eight sera from children with systemic rheumatic diseases were screened for autoantibodies directed against hUBF by indirect immunofluorescence and immunoblotting using MOLT-4 cell extracts. Reactivity with hUBF was confirmed by immunoprecipitation of the recombinant hUBF protein.
  
  
  RESULTS
  Two sera out of 238 (< 1.0%) with reactivity against hUBF were identified. One patient had recurrent abdominal pain, headache, and Raynaud's phenomenon. There has been no evidence of an active systemic rheumatic disease in more than 8 years of followup. The 2nd patient had Raynaud's phenomenon and systemic lupus erythematosus.
  
  
  CONCLUSIONS
  Antibodies to hUBF are rare in children with systemic rheumatic diseases. Raynaud's phenomenon was a clinical feature common to both patients.
authors.affiliation: Department of Medicine, University of Calgary.
authors.forename: M J
authors.initials: MJ
authors.lastname: Fritzler
authors.forename: C A
authors.initials: CA
authors.lastname: von Muhlen
authors.forename: S M
authors.initials: SM
authors.lastname: Toffoli
authors.forename: H L
authors.initials: HL
authors.lastname: Staub
authors.forename: R M
authors.initials: RM
authors.lastname: Laxer
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000032:analysis*; D001324:Autoantigens / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D015151:Immunoblotting; D007223:Infant; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000276:immunology; D035463:Pol1 Transcription Initiation Complex Proteins; D011928:Raynaud Disease / Q000150:complications / Q000276:immunology; D012216:Rheumatic Diseases / Q000276:immunology*; D014157:Transcription Factors / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D004268:DNA-Binding Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D014157:Transcription Factors; C063844:transcription factor UBF