title: Diagnostic evaluation of a synthetic peptide derived from a novel antigen B subunit as related to other available peptides and native antigens used for serology of cystic hydatidosis.
abstract: A synthetic peptide (GU4) derived from an antigen B (AgB) subunit was serologically compared with crude antigen (HCFA); immunopurified AgB and antigen 5 (Ag5), and two other synthetic peptides, for diagnosis of human cystic hydatidosis. GU4 was derived from the sequence of AgB/2, the novel AgB subunit described by us. The other two peptides: 65 (AgB mimotope) and 89-122 (Ag5 mimotope), were described by others. Antigens B and 5 showed higher diagnostic sensitivity than corresponding peptides. All sera reacting with peptides 89-122 and GU4 also reacted with 65. The latter provided three to four times higher sensitivity than the former two peptides, but 30% lower specificity. The diagnostic efficiency of AgB (82%) was higher than those of Ag5 (74%) and HCFA (71%). Interestingly, 89-122 only reacted with hydatid sera, some of which did not react with AgB. Considering positive those reacting with 89-122 or AgB, sensitivity increases from 77% (with AgB) to 82% (combined), while specificity is the same as with AgB (86%). Our results suggest that hydatid serology may be improved by: a) combining several defined antigens (including synthetic peptides), b) design of new E. granulosus-specific mimotopes, which react with the false negative sera (16/90; 18%).
authors.affiliation: Cátedra de Inmunología, Facultades de Química y Ciencias, Universidad de la República, Montevideo, Uruguay.
authors.forename: M
authors.initials: M
authors.lastname: Barbieri
authors.forename: V
authors.initials: V
authors.lastname: Fernández
authors.forename: G
authors.initials: G
authors.lastname: González
authors.forename: V M
authors.initials: VM
authors.lastname: Luaces
authors.forename: A
authors.initials: A
authors.lastname: Nieto
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000947:Antigens, Helminth / Q000276:immunology*; D004443:Echinococcosis / Q000175:diagnosis* / Q000276:immunology; D004446:Echinococcus / Q000276:immunology*; D006801:Humans; D010455:Peptides / Q000737:chemistry / Q000276:immunology
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D010455:Peptides