OBJECTIVES: 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). CONCLUSION: The SSc-LIA has good agreement with conventional techniques for selected antibodies and has good diagnostic utility.
OBJECTIVES: 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). CONCLUSION: The SSc-LIA has good agreement with conventional techniques for selected antibodies and has good diagnostic utility.
Authors: S Hoa; M Hudson; Y Troyanov; S Proudman; J Walker; W Stevens; M Nikpour; S Assassi; M D Mayes; M Wang; M Baron; M J Fritzler Journal: Medicine (Baltimore) Date: 2016-08 Impact factor: 1.889