title: Evaluation of the Vitros ECiQ immunodiagnostic system for detection of anti-Toxoplasma immunoglobulin G and immunoglobulin M antibodies for confirmatory testing for acute Toxoplasma gondii infection in pregnant women.
abstract: Infection with Toxoplasma gondii is often asymptomatic and, when acquired during pregnancy, may lead to connatal toxoplasmosis in the offspring. The newly introduced Vitros anti-Toxoplasma immunoglobulin G (IgG) and IgM assays, designed for the Vitros ECiQ immunodiagnostic system, a fully automated system based on chemiluminescence, were evaluated as a screening method for the serological detection of acute and chronic Toxoplasma infections in the sera of 719 pregnant women. The combination of the Vitros IgG and IgM assays demonstrated a sensitivity and a specificity of 100% for the successful detection of all acute T. gondii infections by comparison with the Sabin-Feldman dye test as the reference test. The Vitros IgG assay parameter revealed a sensitivity of 95.0%, a specificity of 100.0%, a positive predictive value of 100.0%, a negative predictive value of 86.2%, and an overall agreement of 96.2% by comparison with the dye test. Comparison of the Vitros Toxoplasma IgM assay with the immunosorbent agglutination assay yielded values of 77.1%, 99.0%, 97.7%, 88.5%, and 91.1%, respectively. Subsequent receiver operating characteristic curve analysis for the accurate detection of Toxoplasma IgM in acute (n = 90) and chronic (n = 461) infections demonstrated high sensitivity (92.2%) and specificity (81.6%). The combination of a Toxoplasma-specific IgG assay with specific IgM antibody detection has improved the diagnosis of T. gondii infection by decreasing follow-up testing. Nonetheless, positive Toxoplasma IgM test results during pregnancy necessitate confirmatory testing by a reference laboratory to ensure fast and, above all, accurate test results.
authors.affiliation: Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria. david.kasper@meduniwien.ac.at
authors.forename: David C
authors.initials: DC
authors.lastname: Kasper
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Prusa
authors.forename: Michael
authors.initials: M
authors.lastname: Hayde
authors.forename: Nicole
authors.initials: N
authors.lastname: Gerstl
authors.forename: Arnold
authors.initials: A
authors.lastname: Pollak
authors.forename: Kurt R
authors.initials: KR
authors.lastname: Herkner
authors.forename: Rosmarie
authors.initials: R
authors.lastname: Reiter-Reisacher
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D005260:Female; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D011237:Predictive Value of Tests; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000175:diagnosis*
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M