title: Autoantibodies and autoantigens in the urine of SLE patients.
abstract: Autoantibodies against RNA polymerase I (RNAPI), DNA, La and ribosomal P proteins were detected in the urine of systemic lupus erythematosus (SLE) patients, many with normal protein excretion rates. In a number of cases, the antibodies were detectable in the urine but not the serum sample of the same patient. The presence and relative concentrations of the urinary autoantibodies correlated with disease activity. RNAPI antigens were detected in the urine of SLE patients by radioimmunoassay and immunoblotting using rabbit antisera prepared against the purified holoenzyme. Immunoaffinity purification of the rabbit anti-RNAPI with SLE urine proteins resulted in antibodies directed primarily against the largest RNAPI subunit (S1; 194 kDa). Antibodies prepared against recombinant fusion proteins representing the DNA binding regions of human RNAPI(S1) reacted with a 35 kDa SLE urinary protein, a putative fragment of RNAPI(S1). Ribosomal protein P0 was detected in SLE patients' urine by immunoblotting, using rabbit antiserum prepared against recombinant human P1 fusion protein. The relative quantities of urinary P0 correlated with disease status. Analysis of urinary autoantibodies and corresponding antigens in conjunction with analysis of serum autoantibodies may be of value for the purpose of monitoring disease activity.
authors.affiliation: Department of Molecular Biosciences, Haworth Hall, University of Kansas, Lawrence, KS 66045, USA.
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Sciascia
authors.forename: Harold
authors.initials: H
authors.lastname: Dickensheets
authors.forename: Wendy
authors.initials: W
authors.lastname: Picking
authors.forename: Kristina
authors.initials: K
authors.lastname: Robson
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: B Hilda
authors.initials: BH
authors.lastname: Ye
authors.forename: Liangjin
authors.initials: L
authors.lastname: Zhu
authors.forename: Dean A
authors.initials: DA
authors.lastname: Stetler
mesh_terms: D001323:Autoantibodies / Q000276:immunology / Q000652:urine*; D001324:Autoantigens / Q000276:immunology / Q000652:urine*; D018797:Cell Cycle Proteins; D004247:DNA / Q000276:immunology; D004268:DNA-Binding Proteins / Q000276:immunology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000652:urine; D064126:Minichromosome Maintenance Complex Component 3; D009687:Nuclear Proteins / Q000276:immunology; D012318:RNA Polymerase I / Q000276:immunology; D012261:Ribonucleoproteins / Q000276:immunology; D014157:Transcription Factors / Q000276:immunology; D000097585:SS-B Antigen
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D018797:Cell Cycle Proteins; D004247:DNA; D004268:DNA-Binding Proteins; D064126:Minichromosome Maintenance Complex Component 3; D009687:Nuclear Proteins; D012318:RNA Polymerase I; D012261:Ribonucleoproteins; D014157:Transcription Factors; D000097585:SS-B Antigen; C066470:MCM3 protein, human