Table 5. IgM ELISA using recombinant proteins and TLA can discriminate among samples from different patient groups.
ANTIGEN | ROC analysis | ROC cut-off | AUC | Sensitivity, % | Specificity, % |
---|---|---|---|---|---|
SAG2-GRA1-ROP1 | I vs. IV I + II vs. IV I + II vs. III + IV |
0.4660 | 0.9918 0.9941 0.9637 |
91.7 92.4 92.4 |
100 100 86.5 |
SAG2-GRA1-ROP1-AMA1N | I vs. IV I + II vs. IV I + II vs. III + IV |
0.3060 | 0.9995 0.9970 0.9842 |
93.7 90.9 90.9 |
100 100 97.1 |
AMA1N-SAG2-GRA1-ROP1 | I vs. IV I + II vs. IV I + II vs. III + IV |
0.4980 | 1.0000 0.9970 0.9856 |
89.6 84.9 84.9 |
100 100 99.0 |
AMA1C-SAG2-GRA1-ROP1 | I vs. IV I + II vs. IV I + II vs. III + IV |
0.4145 | 0.9991 0.9980 0.9718 |
93.8 92.4 92.4 |
100 100 91.4 |
AMA1-SAG2-GRA1-ROP1 | I vs. IV I + II vs. IV I + II vs. III + IV |
0.3560 | 1.0000 1.0000 0.9942 |
95.8 95.5 95.5 |
100 100 99.0 |
TLA | I vs. IV I + II vs. IV I + II vs. III + IV |
1.0420 | 0.9991 0.9895 0.9626 |
95.8 87.9 87.9 |
100 100 100 |
Serum groups: I–suspected acute phase of T. gondii infection (IgM +; IgG +; low avidity), n = 48. II–chronic T. gondii infection with presence of IgM antibodies (IgM +; IgG +; high avidity), n = 18. III–chronic T. gondii infection with absence of IgM antibodies (IgM–; IgG +; high avidity), n = 58. IV–control group (IgM–; IgG–), n = 46. AUC was determined for the group or groups clusters indicated in the second column. Sensitivity and specificity were determined using the cut-off value obtained by ROC analysis (for each antigen preparation the same cut-off value was adopted for all compared groups–as a result, a lower sensitivity was obtained for some compared groups), for the best discrimination among the groups indicated in each row.