Table 2.
Statistical sensitivity and specificity of Polycheck Celiac IgA and IgG tests for single antibody and for selected multi-antibody combinations
| Specific coeliac antibody | Sensitivity % | Specificity % | PPV % | NPV % | AU ROC | LR+2 | LR- |
| Single antibody positivity | |||||||
| Anti-tTG-IgA1 | 97.7% | 100.0% | 100.0% | 98.0% | 98.9% | - | 0.023 |
| Anti-tTG-IgG | 48.0% | 98.0% | 96.0% | 65.3% | 73.0% | 24.000 | 0.531 |
| Anti-DPG-IgA1 | 34.1% | 98.0% | 93.8% | 62.8% | 68.1% | 17.045 | 0.673 |
| Anti-DPG-IgG | 100.0% | 96.0% | 96.2% | 100.0% | 98.0% | 25.000 | 0.000 |
| Combination of two or more positive antibodies | |||||||
| Anti-tTG-IgA/-IgG + anti-DGP-IgG/-IgA | 98.0% | 100.0% | 100.0% | 98.0% | 99.0% | - | 0.020 |
1
Calculations after excluding patients with selective IgA deficiency;
2
For strategies, where specificity of a test/combination was 100%, the likehood ratio for a positive result could not be calculated. PPV: Positive predictive value; NPV: Negative predictive value; AU ROC: Area under a receiving operator characteristic curve; LR+: Likehood ratio for a positive result; LR-: Likehood ratio for a negative result.