title: Evaluation of a new multi-parallel line immunoassay for systemic sclerosis-associated antibodies in an Asian population.
abstract: OBJECTIVE
  To compare the SSc-line immunoassay (LIA) with conventional techniques of antibody detection, to evaluate its diagnostic utility and to describe clinical associations of antibodies in Asian SSc patients.
  
  
  METHODS
  Stored sera from patients with SSc (n = 68), SLE (n = 49), OA (n = 41) and normal controls (NCs, n = 32) were evaluated. Cohen's κ and Bland-Altman plots were used to evaluate agreement.
  
  
  RESULTS
  There was good agreement between LIA and ELISA for anti-Scl-70 (κ = 0.97), anti-CENPA (κ = 0.83), anti-CENPB (κ = 0.96) and anti-PmScl100 (κ = 1.00) (5.48-8.22% of values outside the 95% limits of agreement using Bland-Altman plots), and between LIA and IIF for anti-CENPA (κ = 0.81) and anti-CENPB (κ = 0.77) (P < 0.001). Using LIA, of 32 (32/68, 47%) SSc patients negative for anti-Scl-70 and anti-CENPA/B, 5 (5/32, 15%) were positive for anti-Ku, -Nor90, -fibrillarin and -RP155. Specificity of each antibody for SSc was at least 97% (vs OA/NC) and 94% (vs SLE), except for anti-Ro52 (63%). Anti-CENPB was associated with joint pain [odds ratio (OR) 0.17], interstitial lung disease (OR 0.24) and telangiectasia (OR 4.00) (P < 0.05). Anti-Ro60 was associated with pulmonary arterial hypertension (OR 3.89, P = 0.041).
  
  
  CONCLUSIONS
  The SSc-LIA has good agreement with conventional techniques for selected antibodies and has good diagnostic utility.
authors.affiliation: Block 6 Level 9, Department of Rheumatology and Immunology, Singapore General Hospital, Outram Road, Singapore 169608. andrea.low.h.l@sgh.com.sg
authors.forename: Andrea H L
authors.initials: AH
authors.lastname: Low
authors.forename: Stephen
authors.initials: S
authors.lastname: Wong
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
authors.forename: Swee Cheng
authors.initials: SC
authors.lastname: Ng
authors.forename: Jia Yuen
authors.initials: JY
authors.lastname: Lim
authors.forename: Xinyi
authors.initials: X
authors.lastname: Ng
authors.forename: Arul
authors.initials: A
authors.lastname: Earnest
authors.forename: Kok Yong
authors.initials: KY
authors.lastname: Fong
mesh_terms: D044466:Asian People; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D016022:Case-Control Studies; D000076247:Centromere Protein A; D051936:Centromere Protein B / Q000276:immunology; D002868:Chromosomal Proteins, Non-Histone / Q000276:immunology; D004264:DNA Topoisomerases, Type I; D004797:Enzyme-Linked Immunosorbent Assay; D005095:Exoribonucleases / Q000276:immunology; D063326:Exosome Multienzyme Ribonuclease Complex; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000276:immunology; D012595:Scleroderma, Systemic / Q000175:diagnosis / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; C000619700:CENPA protein, human; C497926:CENPB protein, human; D000076247:Centromere Protein A; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D009687:Nuclear Proteins; C048100:Scl 70 antigen, human; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C077044:EXOSC10 protein, human; D004264:DNA Topoisomerases, Type I