Table 3.
New sensitivity and specificity of autoantibodies using Youden’s Index for optimal cut-off points in our cohort of patients.
| Autoantibody | Current ELISA Ab cut-off (au) | New ELISA Ab cut-off (au) | AUC (95%CI) | Sensitivity 95% CI (current cut-off) | Sensitivity 95% CI (new cut-off) | Specificity 95% CI (current cut-off) | Specificity 95%CI (new cut-off) |
|---|---|---|---|---|---|---|---|
| Mi2 | 53 | 34.3 | 1 (0.91 – 1) | 94.7 (74-99.9) | 100 (82.4-100) | 100 (94.3-100) | 100 (96-100) |
| MDA5 | 32 | 6.7 | 0.974 (0.91-1) | 80 (56.3-94.3) | 90 (68.3-98.8) | 100 (94.2-100) | 98.4 (91.3-100) |
| ARS Ab | 25 | 22.2 | 0.997 (0.973-1) | 98.6 (92.3-100) | 98.6 (92.3-100) | 99.1 (95.2-100) | 99 (94.5-100). |
| Jo1 | 25 | 20.2 | 1 (0.956-1) | 100 (83.9-100) | 100 (83.9-100) | 100 (94.1-100) | 100 (94.1-100) |
| EJ | 25 | 16.6 | 1 (0.937-1) | 100 (59-100) | 100 (59-100) | 100 (92.9-100) | 100 (92.9-100) |
| KS | 25 | 16.6 | 1 (0.927 -1 | 100 (15.8-100) | 100 (15.8-100) | 100 (92.8-100) | 100 (92.5-100) |
| PL-7 | 25 | 16.6 | 1 (0.91-1) | 100 (83.9-100 | 100 (83.9 – 100) | 100 (94-100) | 100 (93.9-100) |
| PL-12 | 25 | 22.2 | 0.993 (0.94-1) | 94.7 (74-99.9) | 95 (75.14-99.9) | 98.3 (90.8-100) | 100 (93.7 – 100 |