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.