title: Comparative qualitative and quantitative analysis of scleroderma (systemic sclerosis) serologic immunoassays.
abstract: The heterogeneity of autoantibody specificities occurring in sera from patients with systemic sclerosis (SSc) raised the necessity of developing various methodologies for their detection. A cohort of 150 SSc patients were selected and tested by Indirect Immunofluorescence (IIF), Counterimmunoelectrophoresis (CIE), Immunoblot (IB) using various extracts as antigenic source and RNA precipitation. By preparing a nuclear (IB-nuclear) and a metaphase chromosomal-enriched extract (IB-MC-pellet) from HeLa cells as well as a nucleolar (IB-nucleolar) and a histone (IB-histone) extract from rat liver nuclei, we assessed their sensitivity and specificity for anti-Topo I, anti-U3RNP, anti-H1, anti-snRNPs antibodies and ACA. IB-nuclear revealed the highest frequency of anti-Topo I antibodies, while CIE, IB-nucleolar and IB-MC-pellet, when compared to IB-nuclear showed a sensitivity of 89%, 87% and 95%, respectively. IB-MC-pellet was unique for ACA recognition, while IB-nucleolar and IB-MC-pellet showed excellent sensitivity for anti-U3RNP and anti-H1 antibody detection. We conclude that IB-nuclear is a highly sensitive system for anti-Topo I antibodies determination, but CIE reveals a good sensitivity to be used as a first screening test. IB-nucleolar or IB-MC-pellet are important techniques to detect the variety of antibodies to nucleolus and chromatin-related constituents. A novel specificity against a 28kD nucleolar protein, non-associated with RNAs is also presented.
authors.affiliation: Department of Pathophysiology, Medical School, National University of Athens, 75 Mikras Asias Street 115 27 Athens, Greece.
authors.forename: Lefkothea
authors.initials: L
authors.lastname: Picha
authors.forename: Ioannis
authors.initials: I
authors.lastname: Pakas
authors.forename: Apostolia
authors.initials: A
authors.lastname: Guialis
authors.forename: Haralampos M
authors.initials: HM
authors.lastname: Moutsopoulos
authors.forename: Panayiotis G
authors.initials: PG
authors.lastname: Vlachoyiannopoulos
mesh_terms: D000328:Adult; D017668:Age of Onset; D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood* / Q000145:classification; D005260:Female; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting / Q000379:methods*; D008099:Liver / Q000737:chemistry / Q000166:cytology; D008297:Male; D051381:Rats; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods
chemical_list: D001323:Autoantibodies