title: A set of recombinant antigens from Echinococcus granulosus with potential for use in the immunodiagnosis of human cystic hydatid disease.
abstract: Several recombinant clones expressing antigens from Echinococcus granulosus were isolated previously from a parasite cDNA library using cystic hydatid disease (CHD) patients' sera or rabbit hyperimmune antiserum against a lipoproteic fraction from bovine cyst fluid. Six of these antigens were expressed in Escherichia coli and the purified recombinant proteins were tested in enzyme-linked immunosorbent assay (ELISA) for specific IgG with a panel of sera from patients with surgically confirmed (n = 58) or immunologically diagnosed (n = 71) CHD. Sera from clinically normal individuals (n = 203) and sera from individuals with other helminthic infections (n = 65) were assayed for the assessment of specificity. A cut-off value was determined by receiver-operating-characteristic plots for each antigen. A recombinant antigen B subunit (AgB8/2) presented the highest sensitivity (93.1%), considering the group of sera from patients with CHD surgically confirmed, and specificity (99.5%) and is proposed as the basis for an immunodiagnostic test. The other recombinant antigens tested presented sensitivities between 58.6% and 89.7%, and three of them were considered of complementary value. In subclass-specific ELISA, different IgG isotypes showed dominance in the response for each of the recombinant antigens. There was a clear predominance of IgG4 response for all antigens tested, indicating that this would be the subclass of choice to be assessed for these recombinant proteins.
authors.affiliation: Laboratório de Biologia Molecular de Cestódeos, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: V G
authors.initials: VG
authors.lastname: Virginio
authors.forename: A
authors.initials: A
authors.lastname: Hernández
authors.forename: M B
authors.initials: MB
authors.lastname: Rott
authors.forename: K M
authors.initials: KM
authors.lastname: Monteiro
authors.forename: A F
authors.initials: AF
authors.lastname: Zandonai
authors.forename: A
authors.initials: A
authors.lastname: Nieto
authors.forename: A
authors.initials: A
authors.lastname: Zaha
authors.forename: H B
authors.initials: HB
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology / Q000302:isolation & purification*; D019540:Area Under Curve; D016022:Case-Control Studies; D004443:Echinococcosis / Q000175:diagnosis / Q000276:immunology*; D004446:Echinococcus / Q000276:immunology*; D000939:Epitopes / Q000276:immunology / Q000302:isolation & purification; D004926:Escherichia coli / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D012372:ROC Curve; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification; D012698:Serologic Tests
chemical_list: D000947:Antigens, Helminth; D000939:Epitopes; D007074:Immunoglobulin G; D011994:Recombinant Proteins