Parasites, Hosts and Diseases

The Korea Society for Parasitology and Tropical Medicine (대한기생충학·열대의학회)
권호 표지
DOI QR코드

DOI QR Code

IgG Western Blot for Confirmatory Diagnosis of Equivocal Cases of Toxoplasmosis by EIA-IgG and Fluorescent Antibody Test

  • Khammari, Imen (UR 12 SP 34 Research Unit, Ministry of Public Health) ;
  • Saghrouni, Fatma (UR 12 SP 34 Research Unit, Ministry of Public Health) ;
  • Yaacoub, Alia (Laboratory of Parasitology, Farhat Hached Teaching Hospital) ;
  • Meksi, Sondoss Gaied (Laboratory of Parasitology, Farhat Hached Teaching Hospital) ;
  • Ach, Hinda (Laboratory of Parasitology, Farhat Hached Teaching Hospital) ;
  • Garma, Lamia (Laboratory of Parasitology, Farhat Hached Teaching Hospital) ;
  • Fathallah, Akila (Laboratory of Parasitology, Farhat Hached Teaching Hospital) ;
  • Said, Moncef Ben (UR 12 SP 34 Research Unit, Ministry of Public Health)
  • Received : 2013.05.06
  • Accepted : 2013.07.05
  • Published : 2013.08.31
Download PDF
⟨ Previous Next ⟩

Abstract

The performance values of available techniques used in serodiagnosis of toxoplasmosis are satisfactory but they raise problems of equivocal and discordant results for very low IgG titers. Recently marketed, LDBio-Toxo II IgG Western blot (IB) showed an excellent correlation with the dye test. We estimated the proportion of equivocal and discordant results between the enzyme immunoassay Platelia Toxo IgG (EIA-IgG) and fluorescent antibody test (FAT) and assessed the usefulness of the IB as a confirmatory test. Out of 2,136 sera collected from pregnant women, 1,644 (77.0%) tested unequivocally positive and 407 (19.0%) were negative in both EIA-IgG and FAT. The remaining 85 (4%) sera showed equivocal or discordant results. Among them, 73 (85.9%) were positive and 12 (14.1%) were negative in IB. Forty-one (89.1%) equivocal sera in EIA-IgG and 46 (86.8%) equivocal sera in FAT were positive in IB. Reducing the cut-off values of both screening techniques improved significantly their sensitivity in detecting very low IgG titers at the expense of their specificity. In conclusion, equivocal results in routine-used techniques and their discordance in determination of the immune status in pregnancy women were not uncommon. IB test appeard to be highly useful in these situations as a confirmatory technique.

Keywords

References

  1. Robert-Gangneux F, Darde ML. Epidemiology of and diagnostic strategies for toxoplasmosis. Clin Microbiol Rev 2012; 25: 264- 296. https://doi.org/10.1128/CMR.05013-11
  2. Meroni V, Genco F. Toxoplasmosis in pregnancy: evaluation of diagnostic methods. Parassitologia 2008; 50: 51-53.
  3. Montoya JG, Remington JS. Management of Toxoplasma gondii infection during pregnancy. Clin Infect Dis 2008; 47: 554-566. https://doi.org/10.1086/590149
  4. Ashburn D, Evans R, Chatterton JM, Joss AW, Ho-Yen DO. Strategies for detecting Toxoplasma immunity. Br J Biomed Sci 2003; 60: 105-108. https://doi.org/10.1080/09674845.2003.11783684
  5. Kulasiri C. The specificity of the Sabin-Feldman dye test with reference to protozoal infections. J Clin Pathol 1960; 13: 339-348. https://doi.org/10.1136/jcp.13.4.339
  6. Reiter-Owona I, Petersen E, Joynson D, Aspock H, Darde ML, Disko R, Dreazen, O, Dumon H, Grillo R, Gross U, Hade M, Holliman R, Ho-Yen DO, Janitschke K, Jenum PA, Naser K, Olszewski M, Thulliez P, Seitz HM. The past and present role of the Sabin-Feldman dye test in the serodiagnosis of toxoplasmosis. Bull World Health Organ 1999; 77: 929-935.
  7. Franck J, Garin YJ, Dumon H. LDBio-Toxo II immunoglobulin G Western blot confirmatory test for anti-Toxoplasma antibody detection. J Clin Microbiol 2008; 46: 2334-2338. https://doi.org/10.1128/JCM.00182-08
  8. Jost C, Touafek F, Fekkar A, Courtin R, Ribeiro M, Mazier D, Paris L. Utility of immunoblotting for early diagnosis of toxoplasmosis seroconversion in pregnant women. Clin Vaccine Immunol 2011; 18: 1908-1912. https://doi.org/10.1128/CVI.05303-11
  9. Lesle F, Touafek F, Fekkar A, Mazier D, Paris L. Discrepancies between a new highly sensitive Toxoplasma gondii ELISA assay and other reagents: interest of Toxo IgG Western blot. Eur J Clin Microbiol Infect Dis 2011; 30: 1207-1212. https://doi.org/10.1007/s10096-011-1214-1
  10. Kohler S, Rossler D, Hornauer S, Upmeier B, Franck J, Liesenfeld O. Neutralization assay to resolve discrepancies between positive results in new highly sensitive anti-Toxoplasma gondii IgG assays and negative results in reference tests. Eur J Clin Microbiol Infect Dis 2010; 29: 359-363. https://doi.org/10.1007/s10096-009-0864-8
  11. Hofgartner WT, Swanzy SR, Bacina RM, Condon J, Gupta M, Matlock PE, Bergeron DL. Detection of immunoglobulin G (IgG) and IgM antibodies to Toxoplasma gondii: evaluation of four commercial immunoassay systems. J Clin Microbiol 1997; 35: 3313- 3315.
  12. Prusa AR, Hayde M, Unterasinger L, Pollak A, Herkner KR, Kasper DC. Evaluation of the Roche Elecsys Toxo IgG and IgM electrochemiluminescence immunoassay for the detection of gestational Toxoplasma infection. Diagn Microbiol Infect Dis 2010; 68: 352- 357. https://doi.org/10.1016/j.diagmicrobio.2010.07.011
  13. Cimon B, Marty P, Morin O, Bessieres, MH, Marx-Chemla C, Gay-Andrieu F, Thulliez P. Specificity of low anti-Toxoplasma IgG titers with IMx and AxSYM Toxo IgG assays. Diagn Microbiol Infect Dis 1998; 32: 65-67. https://doi.org/10.1016/S0732-8893(98)00060-1
  14. Ashburn D, Chatterton JM, Evans R, Joss AW, Ho-Yen DO. Success in the Toxoplasma dye test. J Infect 2001; 42: 16-19. https://doi.org/10.1053/jinf.2000.0764

Cited by

  1. A New IgG Immunoblot Kit for Diagnosis of Toxoplasmosis in Pregnant Women vol.52, pp.5, 2013, https://doi.org/10.3347/kjp.2014.52.5.493
  2. Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays vol.33, pp.1, 2019, https://doi.org/10.1128/cmr.00130-18
  3. Performance of a Toxo IgM prototype assay for the diagnosis of maternal and congenital Toxoplasma infections vol.58, pp.11, 2020, https://doi.org/10.1515/cclm-2019-1199
  4. Contribution of the Toxoplasma ICT IgG IgM® test in determining the immune status of pregnant women against toxoplasmosis vol.35, pp.5, 2013, https://doi.org/10.1002/jcla.23749
  5. A longitudinal study of Toxoplasma gondii seroconversion on four large Danish sow farms vol.295, pp.None, 2013, https://doi.org/10.1016/j.vetpar.2021.109460