Table 1 Baseline characteristics
|  | HC (n = 22) | iSLE (n = 29) | SLE (n = 39) | p value |
|---|---|---|---|---|
Female gender, n (%) | 18 (82) | 23 (79) | 32 (82) | NS |
Age (years) | 45 (24–65) | 44 (20–83) | 43 (19–76) | NS |
Race, n (%) | ||||
 Caucasian | 100 | 25 (86) | 35 (90) |  |
 Asian | 0 | 2 (7) | 1 (3) |  |
 Other | 0 | 2 (7) | 3 (8) |  |
Disease duration (years) |  | 1.4 (0.1–4.6) | 2.8 (0.5–6.8) | 0.004 |
ACR criteria |  | 3 (1–3) | 5 (2–9) | < 0.0001 |
SLICC criteria |  | 3 (2–4)* | 5 (3–9) | < 0.0001 |
Clinical criteria, n (%) | ||||
 Skin involvement |  | 13 (45) | 21 (54) | 0.46 |
 Photosensitivity |  | 3 (10) | 9 (23) | 0.17 |
 Arthritis |  | 6 (21) | 18 (46) | 0.03 |
 Alopecia |  | 0 | 5 (13) | 0.05 |
 Ulcera |  | 1 (3) | 6 (15) | 0.11 |
 Hematologic |  | 11 (38) | 26 (67) | 0.02 |
 Serositis |  | 2 (7) | 9 (23) | 0.07 |
 Renal |  | 0 | 13 (33) | 0.001 |
 Neurologic |  | 1 (3)** | 2 (5) | 0.48 |
Immunologic criteria, n (%) | ||||
 ANA | 3 (14) | 29 (100) | 39 (100) | NA |
 Anti-dsDNA | 0 | 9 (31) | 32 (82) | < 0.0001 |
 Anti-SSA | 0 | 13 (45) | 13 (33) | 0.59 |
 Anti-Smith | 0 | 2 (7) | 6 (15) | 0.28 |
 Decreased complement | 2 (9) | 4 (14) | 25 (64) | < 0.0001 |
 Antiphospholipid Ab | 0 | 7 (24) | 17 (44) | 0.01 |
 Coombs positive | NA | 4/23 (17) | 7/17 (41) | 0.10 |