Table 2.
Metrics from six classes of aquaporin-4 antibody assays
| NMO Patients | Sensitivity Mean (95% CI)¶ |
Range † | MS Patients | Specificity Mean (95% CI) |
Range | Likelihood Ratios§ |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Assay | Studies | Tested | Pos | Min | Max | Tested | Pos | Min | Max | Accuracy‡ | LR+ | LR− | ||
| CBA | 9 | 266 | 204 | 76.7 (71.6–81.8) | 55.6 | 96.7 | 531 | 1 | 99.8 (99.4–100.2) | 87.5 | 100 | 76.5 | 383.5 | 0.23 |
| FACS | 3 | 89 | 56 | 62.9 (52.9–73.0) | 51.7 | 71.4 | 235 | 2 | 99.1 (98.0–100.3) | 82.4 | 100 | 62.3 | 69.9 | 0.37 |
| ELISA | 5 | 139 | 89 | 64.0 (56.1–72.0) | 48.3 | 71.9 | 203 | 7 | 96.6 (94.0–99.1) | 85.9 | 100 | 61.8 | 18.8 | 0.37 |
| IIF | 15 | 446 | 280 | 62.8 (58.3–67.3) | 40.0 | 95.0 | 1018 | 26 | 97.4 (96.5–98.4) | 87.5 | 100 | 61.2 | 24.2 | 0.38 |
| RIPA | 1 | 37 | 21 | 56.8 (40.8–72.7) | 144 | 4 | 97.2 (94.5–99.9) | 55.2 | 20.3 | 0.44 | ||||
| FIPA | 4 | 152 | 74 | 48.7 (40.7–56.6) | 32.5 | 76.0 | 397 | 2 | 99.5 (98.8–100.2) | 97.4 | 100 | 48.5 | 97.4 | 0.52 |
†
The lowest and highest mean sensitivity/specificity from individual studies in each method category.
‡
Accuracy = (mean sensitivity × mean specificity)/100.
§
Likelihood ratio (LR)+ = sensitivity/(1-specificity), LR− = (1-sensitivity)/specificity.
¶
Ninety-five percentage confidence interval for sensitivity (or specificity) = √((1-sensitivity) × sensitivity/number of tests) × 1.96.
CBA, cell-based assay; ELISA, enzyme-linked immunosorbent assay; FACS, flow cytometry; FlPA, fluorescence immunoprecipitation assay; IIF, indirect immunofluorescence; MS, multiple sclerosis; NMO, neuromyelitis optica; RlPA, radioimmunoprecipitation assay.