title: Specific anti-nuclear antibodies in systemic sclerosis patients with and without skin involvement: an extended methodological approach.
abstract: OBJECTIVE
  To determine how sensitively SSc-associated ANAs are detected by a standard identification algorithm compared with an extensive panel of ANA identification assays, and to assess the distribution of SSc-associated ANAs and SSc organ system involvement in patients without skin involvement (limited SSc).
  
  
  METHODS
  Serum samples from 145 consecutive monocentric SSc patients fulfilling LeRoy and Medgser's criteria for early SSc were studied. ANAs were detected by IIF on HEp-2000 cells and identified by western blotting, protein radio-immunoprecipitation, RNA immunoprecipitation and line immunoassay (LIA). SSc organ involvement was assessed according to a modification of Medsger's disease severity scale.
  
  
  RESULTS
  At least one specific ANA reactivity was present in 88% of the patients. The standard algorithm (IIF and LIA) found at least one specific ANA in 74% of the patients. The main reactivities missed by this algorithm were anti-RNA polymerase III, anti-PM/Scl and anti-Th/To. Eighty-three percent of the patients with limited SSc had at least one ANA. ACAs and anti-Th/To antibodies were significantly associated with limited SSc, whereas anti-topoisomerase I and anti-RNA polymerase III were observed less frequently. SSc organ system involvement was present in 63% of the patients with limited SSc, most of whom had lung involvement.
  
  
  CONCLUSIONS
  Standard algorithms for ANA identification lack sensitivity for the detection of SSc-associated ANA and should be supplemented with additional assays, especially in a clinical environment that has particular interest in SSc. The spectrum of SSc-associated ANA differs according to the presence or absence of skin involvement.
authors.affiliation: Department of Rheumatology, Ghent University Hospital, Ghent University, Ghent, Belgium. jens.vanpraet@ugent.be
authors.forename: Jens T
authors.initials: JT
authors.lastname: Van Praet
authors.forename: Katleen
authors.initials: K
authors.lastname: Van Steendam
authors.forename: Vanessa
authors.initials: V
authors.lastname: Smith
authors.forename: Georges
authors.initials: G
authors.lastname: De Bruyne
authors.forename: Tsuneyo
authors.initials: T
authors.lastname: Mimori
authors.forename: Carolien
authors.initials: C
authors.lastname: Bonroy
authors.forename: Dirk
authors.initials: D
authors.lastname: Elewaut
authors.forename: Dieter
authors.initials: D
authors.lastname: Deforce
authors.forename: Filip
authors.initials: F
authors.lastname: De Keyser
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D015531:Radioimmunoprecipitation Assay / Q000379:methods*; D012594:Scleroderma, Localized / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000097:blood / Q000453:epidemiology / Q000276:immunology*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D000974:Antibodies, Antinuclear