title: A recombinant topoisomerase I ELISA: screening for IgG, IgM and IgA anti-topo I autoantibodies in human sera.
abstract: An ELISA for the detection of anti-topoisomerase I autoantibodies in sera from patients with suspected or manifest rheumatic diseases is described. The antigen source used in this assay consists of a recombinant protein containing the last 695 C-terminal amino acid residues of human topoisomerase I (topo I). The sensitivity of the assay was 61%, while the specificity was more than 98%. Using this ELISA, 47 sera from scleroderma patients and immunopositive for anti-topo I antibodies, were screened for the presence of the isotypes IgG, IgA and IgM to topo I. Our finding that relatively high levels of IgA antibodies to topo I are present in most of the sera tested is consistent with the results of Hildebrandt et al. [1]. In addition, it is demonstrated that the IgG and IgA antibodies in a serum may recognize different epitope regions on the topo I polypeptide.
authors.affiliation: Department of Biochemistry, University of Nijmegen, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Verheijen
authors.forename: B A
authors.initials: BA
authors.lastname: de Jong
authors.forename: W J
authors.initials: WJ
authors.lastname: van Venrooij
mesh_terms: D001323:Autoantibodies / Q000097:blood; D004264:DNA Topoisomerases, Type I / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D011994:Recombinant Proteins / Q000276:immunology; D012595:Scleroderma, Systemic / Q000097:blood / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011994:Recombinant Proteins; D004264:DNA Topoisomerases, Type I