title: Primary biliary cirrhosis-related autoantibodies in a large cohort of italian patients with systemic sclerosis.
abstract: OBJECTIVE
  To analyze the prevalence, associations, and fine specificity of autoantibodies to primary biliary cirrhosis (PBC)-associated antigens (MIT3, Sp100, and gp210) in a cohort of Italian patients with systemic sclerosis (SSc).
  
  
  METHODS
  Sera samples from 201 patients with SSc were tested for antibodies to MIT3, gp210, and Sp100 by ELISA (the PBC screen). Anti-MIT3-positive sera were studied for IgG or IgA isotypes. All sera were analyzed by indirect immunofluorescence on HEp-2 cells and on rodent kidney/stomach/liver tissue sections in order to detect antinuclear and antimitochondrial antibodies (AMA). SSc was selected by American College of Rheumatology criteria and classified based on LeRoy's criteria.
  
  
  RESULTS
  Forty-three (21.4%) sera samples were positive for PBC screen antibodies. Anti-MIT3 antibodies were detected in 36 samples, anti-Sp100 in 5, and anti-gp210 in 1 sample. The other 3 PBC screen-positive samples showed no specificity for the single antigens. PBC screen-positive patients more frequently showed a limited cutaneous SSc subtype (p = 0.04), anticentromere antibodies (ACA; p = 0.0013), elevated alkaline phosphatase (ALP) (p < 0.0001), PBC (p = 0.002), and AMA (p = 0.008). Teleangiectasia and calcinosis were less frequent in this group of patients. IgG+IgA anti-MIT3-positive patients had higher prevalence of AMA (p = 0.0035), diagnosis of PBC (p = 0.014), and increased ALP (p = 0.039), all considered biochemical markers of severe liver disease.
  
  
  CONCLUSIONS
  PBC screen antibodies were detected in 20% of patients with SSc, strongly associated with ACA. ACA+/PBC screen+ patients had higher risk of developing PBC or elevation of ALP.
authors.affiliation: Rheumatology Unit, Spedali Civili, Piazzale Spedali Civili 1, 25100 Brescia, Italy. ilariacava@virgilio.it
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cavazzana
authors.forename: Angela
authors.initials: A
authors.lastname: Ceribelli
authors.forename: Mara
authors.initials: M
authors.lastname: Taraborelli
authors.forename: Micaela
authors.initials: M
authors.lastname: Fredi
authors.forename: Gary
authors.initials: G
authors.lastname: Norman
authors.forename: Angela
authors.initials: A
authors.lastname: Tincani
authors.forename: Minoru
authors.initials: M
authors.lastname: Satoh
authors.forename: Franco
authors.initials: F
authors.lastname: Franceschini
mesh_terms: D000328:Adult; D000368:Aged; D034961:Antigens, Nuclear / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D005260:Female; D006801:Humans; D007558:Italy; D008105:Liver Cirrhosis, Biliary / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D028861:Nuclear Pore Complex Proteins / Q000276:immunology; D011237:Predictive Value of Tests; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012595:Scleroderma, Systemic / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; C558283:MIT3 fusion protein; C063865:NUP210 protein, human; D028861:Nuclear Pore Complex Proteins; D011993:Recombinant Fusion Proteins; C066642:SP100 protein, human