IgG Western Blot for Confirmatory Diagnosis of Equivocal Cases of Toxoplasmosis by EIA-IgG and Fluorescent Antibody Test
2
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
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.
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.
참고문헌 (14)
- Robert-Gangneux F, "Epidemiology of and diagnostic strategies for toxoplasmosis", Clin Microbiol Rev, 25, pp.264~296 (2012)
- Meroni V, "Toxoplasmosis in pregnancy : evaluation of diagnostic methods", Parassitologia, 50, pp.51~53 (2008)
- Montoya JG, "Management of Toxoplasma gondii infection during pregnancy", Clin Infect Dis, 47, pp.554~566 (2008)
- Ashburn D, "Strategies for detecting Toxoplasma immunity", Br J Biomed Sci, 60, pp.105~108 (2003)
- Kulasiri C, "The specificity of the Sabin-Feldman dye test with reference to protozoal infections", J Clin Pathol, 13, pp.339~348 (1960)
- Reiter-Owona I, "The past and present role of the Sabin-Feldman dye test in the serodiagnosis of toxoplasmosis", Bull World Health Organ, 77, pp.929~935 (1999)
- Franck J, "LDBio-Toxo II immunoglobulin G Western blot confirmatory test for anti-Toxoplasma antibody detection", J Clin Microbiol, 46, pp.2334~2338 (2008)
- Jost C, "Utility of immunoblotting for early diagnosis of toxoplasmosis seroconversion in pregnant women", Clin Vaccine Immunol, 18, pp.1908~1912 (2011)
- Leslé F, "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, 30, pp.1207~1212 (2011)
- Köhler S, "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, 29, pp.359~363 (2010)
- Hofgärtner WT, "Detection of immunoglobulin G(IgG)and IgM antibodies to Toxoplasma gondii : evaluation of four commercial immunoassay systems", J Clin Microbiol, 35, pp.3313~3315 (1997)
- Prusa AR, "Evaluation of the Roche Elecsys Toxo IgG and IgM electrochemiluminescence immunoassay for the detection of gestational Toxoplasma infection", Diagn Microbiol Infect Dis, 68, pp.352~357 (2010)
- Cimon B, "Specificity of low anti-Toxoplasma IgG titers with IMx and AxSYM Toxo IgG assays", Diagn Microbiol Infect Dis, 32, pp.65~67 (1998)
- Ashburn D, "Success in the Toxoplasma dye test", J Infect, 42, pp.16~19 (2001)