1. Comparison of four commercially available avidity tests for Toxoplasma gondii-specific IgG antibodies
- Author
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Villard, Odile, Breit, L., Cimon, B., Franck, J., Fricker-Hidalgo, H., Godineau, N., Houze, S., Paris, L., Pelloux, H., Villena, I., Candolfi, E., For Toxoplasmosis, Network From The French National Reference Center, Laboratoire Adaptation et pathogénie des micro-organismes [Grenoble] (LAPM), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Hôpital Bichat - Claude Bernard, Service de parasitologie - mycologie [CHU Pitié-Salpétrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Neuroépidémiologie Tropicale (NET), Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-CHU Limoges-Institut d'Epidémiologie Neurologique et de Neurologie Tropicale-Institut National de la Santé et de la Recherche Médicale (INSERM), and Institut National de Veille Sanitaire
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diagnosis ,multicenter evaluation ,Clinical Biochemistry ,MESH: Reagent Kits, Diagnostic ,Antibody Affinity ,Antibodies, Protozoan ,Immunoglobulin G ,Serology ,0302 clinical medicine ,MESH: Pregnancy ,MESH: Antibody Affinity ,Pregnancy ,Immunology and Allergy ,toxo igg ,MESH: Immunoglobulin G ,0303 health sciences ,immunoglobulin-g igg ,biology ,MESH: Toxoplasma ,MESH: Immunoglobulin M ,3. Good health ,immunocompetent pregnant-women ,MESH: Toxoplasmosis ,Female ,Antibody ,Toxoplasma ,toxoplasmosis ,Microbiology (medical) ,030231 tropical medicine ,Immunology ,chemical and pharmacologic phenomena ,system ,03 medical and health sciences ,Diagnostic Laboratory Immunology ,parasitic diseases ,medicine ,Humans ,MESH: Antibodies, Protozoan ,Avidity ,MESH: Humans ,030306 microbiology ,business.industry ,congenital ,Toxoplasma gondii ,assay ,medicine.disease ,biology.organism_classification ,Virology ,Toxoplasmosis ,Immunoglobulin M ,biology.protein ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,Reagent Kits, Diagnostic ,business ,MESH: Female - Abstract
Toxoplasma infection in pregnant women may cause congenital toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii . However, IgM antibodies are not an accurate marker for discriminating between acute and latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying latent infections in pregnant women who exhibit both IgG and IgM anti- Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and latent toxoplasmosis. The positive predictive value of high avidity to confirm latent toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMérieux) to 95.3% (Abbott), indicating that acute toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti- Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of latent toxoplasmosis.
- Published
- 2013
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