Performance characteristics of ANA and anti-CytAb for antisynthetase syndrome.
| Characteristics | Anti-CytAb Test | ANA Test | Anti-CytAb or Jo1 Test |
|---|---|---|---|
| Sensitivity (95% CI), % | 72 (66–79) | 50 (43–57) | 92.3 (88–96) |
| Specificity (95% CI), % | 89 (86–90) | 6 (5–8) | 88.5 (86–90) |
| Positive predictive value (95% CI), % | 54 (48–60) | 9 (7–11) | 59.8 (54–63) |
| Negative predictive value (95% CI), % | 95 (93–96) | 41 (34–49) | 98.5 (97–99) |
| Positive likelihood ratio (95% CI) | 6.3 (5.2–7.6) | 0.54 (0.47–0.62) | 8.0 (6.8–9.6) |
| Negative likelihood ratio (95% CI) | 0.31 (0.25–0.39) | 7.7 (5.9–10.0) | 0.09 (0.05–0.14) |
| Accuracy, % | 86 | 13 | 89.1 |
ANA: antinuclear antibody; anti-CytAb: anticytoplasmic autoantibody.