Valutazione pilota di un sistema automatico per lo screening anticorpale della toxoplasmosi

The aim of this study was the comparison of a fully automated random access system IMMULITE 2000 (DPC) with a semiautomated system VIDAS (bioMérieux) for the first level detection of Toxoplasma-specific IgG and IgM antibodies. In total, 295 samples were examined for Toxoplasma- specific IgG.The comparison between the VIDAS IgG assay and IMMULITE IgG assay showed the same result for 290 samples (98.3%). Particularly, 220 samples were negative, 70 positive and 4 samples were positive with IMMULITE and equivocal with VIDAS. Only one sample showed a discrepant result: positive with IMMULITE and negative with VIDAS. A total of 124 samples were tested for Toxoplasma-specific IgM and 33 were positive or equivocal with VIDAS IgM assay and 30 of these were also tested for Toxoplasma-specific IgG avidity. The comparison between the VIDAS IgM assay and IMMULITE IgM assay showed the following results: 23 samples were positive in the two systems, 4 samples were equivocal with the VIDAS IgM assay but positive in IMMULITE IgM assay, 6 samples were positive or equivocal in the VIDAS IgM assay but negative in IMMULITE IgM assay.The study of the 6 discrepant samples showed: 2 samples with the presence of natural IgM, 3 samples with a high IgG avidity index and 1 with an intermediate IgG avidity index. IgM was not detected with both assays in any of the other samples.The IMMULITE system seems to be a valuable system for the first level diagnosis of Toxoplasma infection.