title: Diagnosis of toxoplasmosis in pregnancy. Evaluation of latex-protein complexes by immnunoagglutination.
abstract: The aim of this work was to obtain a reagent based on latex particles for ruling out acute toxoplasmosis in pregnant women by immunoagglutination (IA). Latex-protein complexes (LPC) were previously synthesized coupling the recombinant protein of Toxoplasma gondii P22Ag and the homogenate of the parasite to latex particles with different size, chemical functionality and charge density. LPC were tested in IA assays against a panel of 72 pregnant women serum samples. Results were analysed through receiver operating characteristic curves, determining area under the curve (AUC), sensitivity, specificity positive and negative predictive values (PPV and NPV, respectively). It was observed that the antigenicity of proteins was not affected during sensitization by either physical adsorption or covalent coupling. The best results in the sense of maximizing discrimination of low avidity sera from chronic ones were observed for the IA test based on latex particles with carboxyl functionality and the recombinant P22Ag, obtaining an AUC of 0·94, a sensitivity of 100% and a NPV of 100%. In this way, the proposed test could be useful for the toxoplasmosis diagnosis in pregnant women, with the advantages of being cheap, rapid and easy to be implemented.
authors.affiliation: INTEC (Universidad Nacional del Litoral and CONICET),Santa Fe (3000),Argentina.
authors.forename: Leandro E
authors.initials: LE
authors.lastname: Peretti
authors.affiliation: INTEC (Universidad Nacional del Litoral and CONICET),Santa Fe (3000),Argentina.
authors.forename: Verónica D G
authors.initials: VDG
authors.lastname: Gonzalez
authors.affiliation: Laboratorio de Tecnología Inmunológica,Facultad de Bioquímica y Ciencias Biológicas,Universidad Nacional del Litoral,Santa Fe (3000),Argentina.
authors.forename: Iván S
authors.initials: IS
authors.lastname: Marcipar
authors.affiliation: INTEC (Universidad Nacional del Litoral and CONICET),Santa Fe (3000),Argentina.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Gugliotta
mesh_terms: D000372:Agglutination Tests; D000953:Antigens, Protozoan / Q000737:chemistry*; D005260:Female; D006801:Humans; D007840:Latex / Q000276:immunology* / Q000378:metabolism; D011247:Pregnancy; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D000953:Antigens, Protozoan; D007840:Latex; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins
keywords: 
                 Toxoplasma gondii
              ; acute toxoplasmosis; acute-phase recombinant antigen; immunoagglutination; latex–protein complexes