Table 2.
Discriminative Performance of Serum Antiglycopeptidolipid Core IgA Antibody at Manufacturer’s Cut Off and Optimal Cut Off Suggested in This Study
| Variable | Cut Off | Glycopeptidolipid IgA, U/mL | Sensitivity, % | Specificity, % | PPV, % | NPV, % | PLR | NLR |
|---|---|---|---|---|---|---|---|---|
| NTM-PD screening in bronchiectasis cohort (n = 240) | Manufacturer’s cut off | ≥ 0.7 | 61.5 | 98.6 | 84.2 | 95.5 | 43.9 | 0.4 |
| Optimal cut offa | ≥ 0.4 | 80.8 | 88.3 | 45.5 | 97.4 | 6.9 | 0.2 | |
| NTM-PD differentiation from NTM isolation (n = 44) | Manufacturer’s cut off | ≥ 0.7 | 65.4 | 94.4 | 94.4 | 65.4 | 11.8 | 0.4 |
| Optimal cut offa | ≥ 0.7 | 65.4 | 94.4 | 94.4 | 65.4 | 11.8 | 0.4 |
NLR = negative likelihood ratio; NPV = negative predictive value; NTM = nontuberculous mycobacteria; NTM-PD = nontuberculous mycobacterial pulmonary disease; PLR = positive likelihood ratio; PPV = positive predictive value.
a
Determined by Youden’s index (sensitivity + specificity – 1).