Table 3.

Specificities and sensitivities for various fold increases of IgG-Ptx, estimated with a mixture model on paired sera with IgG-Ptx levels between 5 and 25 IU/ml in the first sample

Fold increase in IgG-Ptx	Specificity (%)	Sensitivity (%)
1.0	51.1	100.0
1.25	70.5	100.0
1.50	83.0	100.0
2.0	94.7	99.8
3.0	99.4	99.3
4.0	99.9	98.2
6.0	100.0	94.5
8.0	100.0	89.4