Table 2.
Comparison of a commercial avidity test using TLA and an in-house ELISA with the MIC1-MAG1 chimeric antigen based on results for 28 sera from patients in the acute or chronic phase of T. gondii infection
| Serum sample groupa and antigen | No. (%) of samplesb |
Mean AI (range) | ||
|---|---|---|---|---|
| Low AI | Borderline AI | High AI | ||
| Acute phase of toxoplasmosis | ||||
| TLA (VIDAS) | 14 (100) | 0 | 0 | 0.13 (0.11–0.15) |
| MIC1-MAG1, 6 M urea | 1 (7) | 3 (21.5) | 10 (71.5) | 0.43 (0.12–0.63) |
| MIC1-MAG1, 8 M urea | 9 (64.5) | 2 (14) | 3 (21.5) | 0.30 (0.10–0.56) |
| Chronic phase of toxoplasmosis | ||||
| TLA (VIDAS) | 0 | 0 | 14 (100) | 0.52 (0.44–0.65) |
| MIC1-MAG1, 6 M urea | 0 | 0 | 14 (100) | 0.71 (0.56–0.86) |
| MIC1-MAG1, 8 M urea | 0 | 0 | 14 (100) | 0.55 (0.44–0.76) |
a
Fourteen serum samples from each group were examined.
b
Shown is the number of serum samples that reacted. For TLA (VIDAS), an AI below 0.2 is low, an AI of 0.2 to 0.3 is borderline, and an AI over 0.3 is high; for MIC1-MAG1, an AI below 0.3 is low, an AI of 0.3 to 0.4 is borderline, and an AI over 0.4 is high.