Table II.
Optimal cutoffs for the parameters of BAT to peanut with the largest area under the ROC curve (n = 92)
| BAT parameters | Cutoff | AUC ROC | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | LR+ | LR− | Diagnostic accuracy (%) |
|---|---|---|---|---|---|---|---|---|---|
| %CD63+ peanut extract 100 ng/mL | 8.11 (2.93-16.47) | 0.97 (0.93-1.0) | 97.6 (87.4-99.9) | 96.0 (86.3-99.5) | 95.3 (84.2-99.4) | 98.0 (89.1-99.9) | 24.4 (6.3-95.0) | 0.02 (0.0-0.17) | 96.7 (93.1-100) |
| SI CD203c peanut extract 100 ng/mL | 1.88 (1.62-2.24) | 0.96 (0.91-1.0) | 95.2 (83.8-99.4) | 96.0 (86.3-99.5) | 95.2 (83.8-99.4) | 96.0 (86.3-99.5) | 23.8 (6.1-92.7) | 0.05 (0.01-0.19) | 95.7 (91.5-99.8) |
| Mean %CD63+ peanut extract 10-100 ng/mL | 4.78 (4.78-11.76) | 0.97 (0.93-1.0) | 97.6 (87.4-99.9) | 96.0 (86.3-99.5) | 95.3 (84.2-99.4) | 98.0 (89.1-99.9) | 24.4 (6.3-95.0) | 0.02 (0.0-0.17) | 96.7 (93.1-100) |
| Mean SI CD203c peanut extract 10-100 ng/mL | 1.40 (1.40-1.75) | 0.97 (0.94-1.0) | 100.0 (91.6-100) | 94.0 (83.5-98.7) | 93.3 (81.7-98.6) | 100.0 (92.5-100) | 16.7 (5.6-49.9) | —∗ | 96.7 (93.1-100) |
Values in parentheses represent 95% CI.
AUC, Area under the ROC curve; LR+, positive likelihood ratio; LR−, negative likelihood ratio; MFI, mean fluorescence intensity; %CD63+, percentage of CD63-positive basophils (corrected for the negative control); SI CD203c, stimulation index of CD203c (MFI CD203c poststimulation/MFI CD203c of negative control).
∗
LR− could not be determined because sensitivity was 100%.