Autoantibodies to the nucleolar organizer antigen NOR-90 in children with systemic rheumatic diseases.
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.
Fritzler
M J
MJ
Department of Medicine, University of Calgary.
von Muhlen
C A
CA
Toffoli
S M
SM
Staub
H L
HL
Laxer
R M
RM
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*
D001323:Autoantibodies; D001324:Autoantigens; D004268:DNA-Binding Proteins; D035463:Pol1 Transcription Initiation Complex Proteins; D014157:Transcription Factors; C063844:transcription factor UBF