title: Comparison of Toxoplasma gondii IgG avidity Architect and Vidas assays with the estimated date of infection in pregnant women.
abstract: A maternal Toxoplasma gondii infection during pregnancy is a risk for congenital infection through maternal-fetal transplacental transmission. Estimation of the date of infection is of the utmost importance for management and treatment recommendations. In this setting, IgG avidity has been shown to be useful as high avidity rules out an infection dating less than 4 months. The estimated date of infection can also be obtained by the ratio of T. gondii IgG titers measured by the Vidas (bioMérieux) assay versus T. gondii IgG titers measured by the Architect (Abbott Laboratories) test, together with T. gondii IgM and IgA antibody responses. In this study, using 117 serum samples from pregnant women, we compared the IgG avidity values obtained by Architect and Vidas with the presumed date of T. gondii infection established by the T. gondii IgG ratio of IgG Vidas and IgG Architect plus the IgM and IgA results. To date, IgG avidity Vidas seems to exhibit better performance than Architect. For both assays, gray zone results were most likely obtained from patients infected more than 4 months before sampling. These data should be taken into account for a possible reconsideration of the interpretation of avidity results in the gray zone.
authors.affiliation: Laboratoire de Biologie Médicale, Centre Hospitalier de la Dracénie, 83300 Draguignan, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Smets
authors.affiliation: Service de Santé Publique, Unité EVARISQ, CHU Poitiers, 86021 Poitiers, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fauchier
authors.affiliation: Université de Nice Sophia Antipolis, Faculté de Médecine, 06107 Nice, France - INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Toxines Microbiennes dans la relation hôte-pathogènes, 06200 Nice, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Michel
authors.affiliation: Université de Nice Sophia Antipolis, Faculté de Médecine, 06107 Nice, France - INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Toxines Microbiennes dans la relation hôte-pathogènes, 06200 Nice, France - Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Nice, 06202 Nice, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Marty
authors.affiliation: Université de Nice Sophia Antipolis, Faculté de Médecine, 06107 Nice, France - INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Toxines Microbiennes dans la relation hôte-pathogènes, 06200 Nice, France - Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Nice, 06202 Nice, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Pomares
mesh_terms: D000208:Acute Disease; D000913:Antibodies, Protozoan / Q000097:blood; D000915:Antibody Affinity; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood; D007159:Immunologic Tests / Q000379:methods / Q000592:standards; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology / Q000469:parasitology; D013997:Time Factors; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M