Microparticle enzyme immunoassay (MEIA) for toxoplasma specific immunoglobulin G in comparison to the Sabin-Feldman dye test. A pilot study.

The microparticle enzyme immunoassay (MEIA) for detection of Toxoplasma specific IgG antibodies was compared to the Sabin-Feldman dye test (DT) as reference in 843 serum samples from a cohort of 757 pregnant women. The overall correlation for individual measurements was highly significant (R = 0.9446, p < 0.0001). DT and specific IgM combined allowed definition of 3 groups of patients: group 1 (no infection), group 2 (latent infection), group 3 (acute infection). A significant difference was found between the groups for the corresponding IgG values, as determined by the MEIA method, which allowed the following cut-off points to be laid down: group 1: 0-5.2 IU/ml, group 2: 5.3-187.5, and group 3: 187.6 IU/ml and higher. The validity of the cut-off points was tested in a subgroup of 57 patients who underwent serological follow-up during pregnancy. All 15 acutely- and 14 non-infected women, as well as 25 out of 28 latent infections were identified correctly. 3 latent infection were allocated falsely as acute. The threshold values presented in this report need to be confirmed in a large prospective study.