TABLE 2.
Comparison of the specificity of the Platelia and BioPlex 2200 toxoplasma IgM test results for 402 serum samples
| Group | Number (n) | Platelia toxoplasma IgM
|
BioPlex 2200 toxoplasma IgM
|
||
|---|---|---|---|---|---|
| Positive | Negative | Positive | Negative | ||
| Healthy donors | 198 | 0 | 198 | 0 | 198 |
| Pregnant women | 204 | 3a | 201 | 3a | 201 |
| Total (% positive) | 402 | 3 (0.7%) | 399 | 3 (0.7%) | 399 |
a
While the number of positive samples identified by the Platelia and BioPlex 2200 toxoplasma IgM assays among pregnant women was the same, the two assays identified different samples as positive. All of the positive results had signals that were less than 1.5 times the cutoff. The reference laboratory results for these six positive samples were negative, and hence these samples were designated as false positives.