TABLE 6.
Comparison of results between Toxo IgM Architect and ICT from 50 sera (corresponding to 24 women) with seroconversion and 33 sera with nonspecific IgMa
| No. of sera tested | Architect IgM (AU/ml; range) | ICT (% positive) | IgM reference technique [Platelia or ISAgA (range)] | Architect IgG (IU/ml) | Conclusion |
|---|---|---|---|---|---|
| Proved seroconversion (n = 50) | 98 | ||||
| 1 (1 M) | 0.34 | Neg | Neg; 1 ISAgA (5) | 0 | Beginning of IgM increasing |
| 2 (2 M) | 0.39–0.39 | Pos | Pos; 2 ISAgA (9–9) | <0.2 | Beginning of IgM increasing |
| 14 (2 M, 12 SE) | 0.78–9.04 | Pos | Pos; 2 ISAgA (10–12); 12 Platelia (2.84–9.87) | <1.5 | IgM positive (all techniques) |
| 33 (19 M, 14SE) | 0.55–20.61 | Pos | Pos; 19 ISAgA (9–12); 14 Platelia (1.18–9.38) | ≥1.5 | Proved seroconversion |
| No IgG seroconversion (n = 33), no specific IgM | 6 | ||||
| 8 (8 SE) | 0.30–0.49 | Neg | Neg; 8 Platelia (0.10–0.78) | <0.2 | Absence of IgM |
| 2 (2 SE) | 0.5–0.59 | Neg | Neg; 2 Platelia (0.45–0.65) | <0.2 | Absence of IgM |
| 10 (4 M, 6 SE) | 0.63–1.08 | Neg | Neg; 4 ISAgA (0–2); 6 Platelia (0.23–0.78) | <0.2 | False-positive IgM Architect |
| 11 (7 M, 4 SE) | 0.76–1.80 | Neg | Pos; 7 ISAgA (9–11); 4 Platelia (1.30–2.17) | <0.2 | False-positive IgM Architect and reference technique |
| 2 (2 SE) | 0.69–3.96 | Pos | Pos; 2 Platelia (1.23–2.58) | 1, 0.2 | False-positive Architect, ICT, and reference technique |
a
The following cutoffs were used: Architect IgM (Abbott Diagnostics, Wiesbaden, Germany), 0.5 to 0.6 AU/ml; Platelia Toxo IgM (Bio-Rad, Marne la Coquette, France), 0.8 to 1.0; ISAgA IgM (bioMérieux, Marcy l'Etoile, France), 6 to 9.