title: Value of 2 IgG avidity commercial tests used alone or in association to date toxoplasmosis contamination.
abstract: Toxoplasmosis acquired during pregnancy exposes the fetus to congenital toxoplasmosis. Avidity tests are commonly used to date time of infection to evaluate the fetal risk and to offer prenatal diagnosis. This study evaluated and compared 2 commercial avidity tests: Platelia Toxo IgG Avidity (Bio-Rad, Marnes la Coquette, France) and Liaison(R) Toxo IgG Avidity II (Diasorin, Saluggia, Italy) kits. In complement, a study of specific IgG and IgM in the 2 systems was carried out. Sensitivity and specificity of the avidity tests were 94.4% and 87.8% for the Liaison(R) and 91.3% and 98.5% for the Platelia methods, respectively. Percentages of complete discrepancies, partial discrepancies, and agreement between both tests were 1.1%, 23.6%, and 75.3%, respectively. Moreover, the combination of both avidity tests may be useful in some cases. Indeed, that strategy permitted to confirm without delay a chronic toxoplasmosis in 23 cases and avoid treatment in these pregnant women.
authors.affiliation: Université Montpellier I, Centre Hospitalier Universitaire, Nîmes, France. llachaud@gmail.com
authors.forename: Laurence
authors.initials: L
authors.lastname: Lachaud
authors.forename: Olivier
authors.initials: O
authors.lastname: Calas
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Picot
authors.forename: Sahar
authors.initials: S
authors.lastname: Albaba
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bourgeois
authors.forename: Francine
authors.initials: F
authors.lastname: Pratlong
mesh_terms: D000915:Antibody Affinity / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood; D007231:Infant, Newborn; D011247:Pregnancy; D012680:Sensitivity and Specificity; D013997:Time Factors; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M