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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

1998; Wiley; Volume: 20; Issue: 2 Linguagem: Inglês

10.1046/j.1365-3024.1998.00117.x

1365-3024

Mariela Barbieri, Verónica Fernández, Gualberto González‐Sapienza, Víctor Martínez-Luaces, Alberto Nieto,

Coccidia and coccidiosis research

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%) .