Clinical Phenotypes of Patients with Anti-DFS70/LEDGF Antibodies in a Routine ANA Referral Cohort
Table 2
Discrimination of SARD and non-SARD using ANA ELISA, anti-DFS70 CIA, and ANA/DFS70 score (ANA divided by DFS70); different cut-offs.
SARD
Non-SARD
Sensitivity
Specificity
LR+/LR−
DFS pattern#
12/70 (17.1%)
88/130 (67.7%)
67.7% (58.9–75.6%)
82.9% (72.0–90.8%)
2.57/0.25
QUANTA Flash DFS70#
Cut-off 20 CU&
15/70 (21.4%)
79/130 (60.8%)
60.8% (51.8–69.2%)
78.6% (67.1–87.5%)
2.84/0.50
Cut-off 199 CU+
2/70 (2.9%)
25/130 (19.2%)
19.2% (12.8–27.1%)
97.1% (90.1–99.7%)
6.73/0.83
ANA Screen ELISA*
Cut-off 20 units
58/70 (82.9%)
44/130 (33.8%)
82.9% (72.0–90.8%)
66.2% (57.3–74.2%)
2.45/0.26
Cut-off 60 units+
42/70 (60.0%)
10/130 (7.7%)
60.0% (47.6–71.5%)
92.3% (86.3–96.2%)
7.80/0.43
Cut-off 131.2 units+
17/70 (24.3%)
3/130 (2.3%)
24.3% (14.8–36.0%)
97.7% (93.4–99.5%)
10.5/0.76
ANA/DFS70 Score*
ANA divided by DFS70 Cut-off 19.7 CU+
36/70 (51.4%)
3/130 (2.3%)
51.4% (39.2–63.6%)
97.7% (93.4–99.5%)
22.3/0.50
*Positive result (and LR+) considered indicative for SARD; #positive result (and LR+) considered indicative for non-SARD; & cut off values were previously established; +cutoff values were defined based on receiver operating characteristics (ROC) analysis.
