title: Diagnostic and clinical utility of antibodies against the nuclear body promyelocytic leukaemia and Sp100 antigens in patients with primary biliary cirrhosis.
abstract: BACKGROUND
  The lack of an immunoassay that detects antibodies to promyelocytic leukaemia (PML) protein, the primary biliary cirrhosis (PBC)-specific multiple nuclear dot (MND) antigen, has prompted us to develop a line immunoassay (LIA) for the simultaneous detection of PML and Sp100 MND-specific autoantibodies.
  
  
  METHODS
  PML and Sp100 were expressed in Escherichia coli, and analysed by SDS-PAGE and immunoblotting using a monoclonal antibody and MALDI-ToF fingerprinting. A quantitative PML and Sp100 LIA were developed and testing was performed in 150 anti-mitochondrial antibody (AMA) positive, 20 AMA-PBCs and 130 controls.
  
  
  RESULTS
  Thirty-five (23%) of 150 AMA+ PBCs (18 anti-MND+) were anti-PML+ (12%) or anti-Sp100+ (20%), 10 being anti-PML+/Sp100+, 5 single anti-PML+ and 20 single anti-Sp100+. Six (30%, 5 anti-MND+) AMA-PBCs were anti-PML+ or Sp100+. Only 2 (1.7%) pathological controls were anti-PML+ and/or anti-Sp100+. Levels of anti-PML correlated with those of anti-Sp100 (R=0.64, p<0.0001). The autoantibody profile largely remained unchanged over a 10year-follow up (52 patients, 352 samples). Anti-PML, Sp100 or MND-reactive PBCs were younger and had longer disease duration than the seronegative (p=0.06, for both). Anti-Sp100 levels correlated with the Mayo risk score (r=0.63, p=0.01). Anti-PML+/Sp100+ patients had more advanced disease compared to patients negative for anti-PML/Sp100 (p=0.04).
  
  
  CONCLUSIONS
  The new line immunoassay offers a robust and accurate method for the detection of clinically-relevant PBC-specific anti-MND antibodies.
authors.affiliation: Liver Immunopathology, Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, London, UK.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Mytilinaiou
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Meyer
authors.forename: Thomas
authors.initials: T
authors.lastname: Scheper
authors.forename: Eirini I
authors.initials: EI
authors.lastname: Rigopoulou
authors.forename: Christian
authors.initials: C
authors.lastname: Probst
authors.forename: Andreas L
authors.initials: AL
authors.lastname: Koutsoumpas
authors.forename: Daniel
authors.initials: D
authors.lastname: Abeles
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Burroughs
authors.forename: Lars
authors.initials: L
authors.lastname: Komorowski
authors.forename: Diego
authors.initials: D
authors.lastname: Vergani
authors.forename: Dimitrios P
authors.initials: DP
authors.lastname: Bogdanos
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D034961:Antigens, Nuclear / Q000032:analysis / Q000097:blood* / Q000235:genetics / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000032:analysis / Q000097:blood* / Q000235:genetics / Q000276:immunology; D016022:Case-Control Studies; D004926:Escherichia coli / Q000235:genetics; D005500:Follow-Up Studies; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D015473:Leukemia, Promyelocytic, Acute / Q000175:diagnosis* / Q000276:immunology*; D008105:Liver Cirrhosis, Biliary / Q000175:diagnosis / Q000276:immunology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D013997:Time Factors
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; C066642:SP100 protein, human