Table 3.
Concordance between different assay platforms for the detection of anti-DFS70/LEDGFp75 autoantibodies in selected ANA-positive human sera
| Serum | ANA pattern (1:160 dilution) | DFS70-ELISA (cut-off = OD >15 U/mL, 2 SD) | WB (reactivity with 70–75 kDa band) | DFS70-CIA (cut-off = 20 CU) |
|---|---|---|---|---|
| DM-03 | NFS (mc −) | 2.63 | Negative | 1.5 |
| DM-037 | Weak NFS (mc −) | 1.60 | Negative | <1.0 |
| DM-041 | Weak NFS (mc −) | 3.21 | Negative | <1.0 |
| DM-095 | Weak NFS (mc −) | 3.09 | Negative | <1.0 |
| DM-104 | Weak NFS (mc −) | 2.41 | Negative | <1.0 |
| DM-105 | Weak NFS (mc −) | 3.32 | Negative | 1.5 |
| DM-119 | Strong DFS mixed | 80.76 | Strong positive with other multiple reactive bands | 265.3 |
| DM-156 | Weak NFS (mc −) | 2.29 | Negative | <1.0 |
| RA-860 | NFS (mc −) | 1.80 | Negative | <1.0 |
| RA-862 | Strong NFS (mc −) | 1.70 | Negative | 1.2 |
| RA-866 | Weak NFS (mc −) | 3.10 | Negative | <1.0 |
| RA-869 | Weak NFS (mc −) | 1.30 | Negative | <1.0 |
| RA-880 | Weak DFS | 19.18 | Weak positive | 23.0 |
| RA-895 | Weak NFS (mc −) | 2.90 | Negative | <1.0 |
| RA-903 | Weak NFS (mc −) | 1.90 | Negative | <1.0 |
| RA-907 | Very weak nuclear homogeneous | 24.38 | ND | ND |
| RA-909 | Strong DFS | 105.79 | Strong positive | 123.8 |
| RA-912 | Nuclear coarse speckled | 0.60 | Negative | <1.0 |
| OB-033 | Weak NFS (mc −) | 0.92 | Negative | <1.0 |
| OB-041 | Strong DFS | 106.87 | Strong positive | 166.2 |
| OB-101 | Weak NFS (mc −) | 0.92 | Negative | <1.0 |
| OB-156 | Weak NFS (mc −) | 38.72 | Weak positive | 72.8 |
| OB-163 | Weak NFS (mc −) | 0.80 | Negative | <1.0 |
| OB-165 | Weak homogeneous | 5.84 | Negative | 1.2 |
| HI-808 | Weak DFS | 32.27 | Weak positive | 46.3 |
| HI-817 | Weak DFS | 32.47 | Moderately strong positive | 45.9 |
| HI-820 | NFS (mc −) | 0.50 | Negative | <1.0 |
| HI-825 | Weak NFS (mc −) | 1.30 | Negative | <1.0 |
| HI-829 | Strong DFS | 103.10 | Strong positive | 308.1 |
| HI-840 | Weak DFS | 38.06 | Weak positive | 24.5 |
| HI-847 | Weak NFS (mc −) | 1.60 | Negative | <1.0 |
| HI-849 | Weak NFS (mc −) | 2.00 | Negative | <1.0 |
ANA antinuclear antibody, DFS dense fine speckled, DFS70 dense fine speckled autoantigen of 70 kDa, CIA chemiluminescent assay, CU chemiluminescent units, DM dermatomyositis, ELISA enzyme-linked immunosorbent assay, HI healthy individuals, mc − mitotic chromatin negative, NFS nuclear fine speckles, ND not determined, OB obesity, OD optical density, RA rheumatoid arthritis, SD standard deviation, WB Western blotting