title: Autoantibodies to the transcriptional factor SOX13 in primary biliary cirrhosis compared with other diseases.
abstract: The molecule SOX13 was initially identified as an autoantigen (ICA12) in Type 1 diabetes. SOX13 is a member of the SOX family of transcriptional regulatory proteins that contain a high mobility group (HMG) motif with structural similarity to HMG proteins 1 and 2. Antibodies to HMG 1 and 2 occur in autoimmune diseases of the liver and in ulcerative colitis. We measured the occurrence and levels of anti-SOX13 by radioimmunoprecipitation in primary biliary cirrhosis (PBC) and other diseases, and compared frequencies with anti-HMG measured by ELISA. Anti-SOX13 was detected in 18% of patients with PBC, 13% with autoimmune hepatitis, 18% with Type 1 diabetes, at lower frequencies in other conditions including the multisystem autoimmune diseases, systemic lupus erythematosus and rheumatoid arthritis, and in 1% of normal sera. Anti-HMG1 and anti-HMG2 occurred at frequencies of 30% and 35% respectively in PBC. Serum levels of anti-SOX13 and anti-HMG correlated significantly for PBC although not for Type 1 diabetes. Anti-SOX13 in PBC may occur merely as an immune response to products of damage to parenchymal tissue, or may be illustrative of a general proclivity of transcriptional regulatory proteins to elicit autoimmune responses.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Fida
authors.forename: Mark A
authors.initials: MA
authors.lastname: Myers
authors.forename: Senga
authors.initials: S
authors.lastname: Whittingham
authors.forename: Merrill J
authors.initials: MJ
authors.lastname: Rowley
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ozaki
authors.forename: Ian R
authors.initials: IR
authors.lastname: Mackay
mesh_terms: D034961:Antigens, Nuclear / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D015153:Blotting, Western; D024243:HMGB1 Protein / Q000276:immunology; D024261:HMGB2 Protein / Q000276:immunology; D006609:High Mobility Group Proteins / Q000276:immunology*; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology; D009687:Nuclear Proteins / Q000276:immunology; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000276:immunology; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; D055755:SOXD Transcription Factors
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; D024243:HMGB1 Protein; D024261:HMGB2 Protein; D006609:High Mobility Group Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C491720:SOX13 protein, human; D055755:SOXD Transcription Factors; C066642:SP100 protein, human; C516862:PTPRN protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8