Antibodies to fibrillarin, PM-Scl and RNA polymerase III detected by ELISA assays in patients with systemic sclerosis

Danilo Villalta, Gabriella Morozzi, Marilina Tampoia, Claudia Alpini, Ignazio Brusca, Valeria Salgarolo, Wolfgang Papisch, Nicola Bizzaro

Research output: Contribution to journalArticlepeer-review


Background: Anti-fibrillarin (AFA), anti-RNA polymerase (anti-RNAP), and anti-PM-Scl autoantibodies are useful markers for the diagnosis of systemic sclerosis (SSc) in patients who are anti-centromere- (ACA) or anti-topoisomerase I (anti-topo I)-negative, but, until recently, the only specific method for their identification was the radio-immunoprecipitation assay.The aim of this study was to evaluate the clinical accuracy of the new enzyme-linked immunosorbent assays (ELISA) developed by Phadia for their detection. Methods: Sera of 50 ACA and anti-topo I-negative SSc patients, and, as control group, sera of 122 patients (42 with SSc, ACA or anti-topo I-positive, 40 with systemic lupus erythematosus and 40 with rheumatoid arthritis) were studied. Result: Using the cutoff proposed by the manufacturer (10. AU/mL), sensitivity and specificity were: for AFA, 22% and 92.6%; for anti-RNAP, 16% and 97.5%; and for anti-PM-Scl, 8% and 98.8%, respectively. Using a cutoff corresponding to 98.8% specificity for all three antibodies, sensitivity was 10%, 14% and 8%, respectively. The combined use of these three antibody assays enabled identification of 32% of ACA- and anti-topo I-negative SSc patients. Conclusions: These new ELISA methods for AFA, anti-RNAP III and anti-PM-Scl detection have good diagnostic specificity, and may help identify a subset of SSc patients ACA and anti-topo I-negative.

Original languageEnglish
Pages (from-to)710-713
Number of pages4
JournalClinica Chimica Acta
Issue number9-10
Publication statusPublished - 2010


  • Anti-fibrillarin (AFA) antibodies
  • Anti-PM-Scl antibodies
  • Anti-RNA polymerase (anti-RNAP) antibodies
  • Enzyme-linked immunosorbent assay (ELISA)
  • Sensitivity
  • Specificity
  • Systemic sclerosis (SSc)

ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Biochemistry, medical


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