Serological diagnosis of toxoplasmosis in pregnancy: comparison between a manual commercial ELISA assay and the automated VIDAS® kit

• Published in: European journal of clinical microbiology & infectious diseases 2023-06, Vol.42 (6), p.759-769
• Main Authors: Dambrun, Magalie, Sare, Nawal, Vianou, Bertin, Amagbégnon, Richard, Fievet, Nadine, Massougbodji, Achille, Houzé, Sandrine, Migot-Nabias, Florence
• Format: Article
• Language: English
• Subjects: Antibodies, Protozoan; Antibody Affinity; Antigens; Assaying; Avidity; Biomedical and Life Sciences; Biomedicine; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunization; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Internal Medicine; Medical Microbiology; Original Article; Parasites; Pregnancy; Proteins; Reproducibility of Results; Robustness; Serology; Toxoplasma; Toxoplasmosis
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-023-04603-y

Knowledge of the toxoplasmosis serological status in pregnant women is important to allow adequate management for the prevention of congenital toxoplasmosis of those who are not immunized. Serological screening is generally carried out using commercial kits to determine the presence or absence of immunoglobulins M or G in the maternal blood. Robust results are therefore needed. We evaluated the performances of a commercial ELISA assay composed of several recombinant parasite antigens and of a commercial assay using parasite lysate to determine the serological status against Toxoplasma gondii of African pregnant women. A recruitment of 106 pregnant women during their third trimester of pregnancy was carried out in Benin. Serologies were performed with recom Well Toxoplasma IgM and IgG kits. Subsequently, the serological assays were carried out by an automaton method with the VIDAS ® TOXO IgM and IgG II kits. Here we compared recom Well Toxoplasma to VIDAS ® TOXO results. Reproducibility tests of the recom Well kits were assessed following the discrepancies observed in the results. Of 106 plasmas tested, 47 showed anti- T.   gondii IgG (44.3%), including 5 with IgM and high IgG avidity (4.7%). Of the two techniques, VIDAS ® TOXO was more robust and specific for IgG while the recom Well Toxoplasma gave more false positive results. The combination of several techniques for the determination of serological toxoplasmosis status remains relevant. Methods using native proteins are closer to the reality of the environment. Therefore, kits using recombinant proteins should be tested on highly geographically diverse populations to refine their composition.