The baseline characteristics of patients in SLE group and control group
| Characteristics | SLE group (n=352) | Control group (n=385) | P value |
| Sex female, n (%) | 322 (91.5) | 279 (72.5) | <0.001 |
| Age, years* | 36.0 (13.0–81.0) | 55.0 (16.0–83.0) | <0.001 |
| <40, n (%) | 204 (58.0) | 88 (22.9) | <0.001 |
| ≥40, n (%) | 148 (42.0) | 297 (77.1) | <0.001 |
| Disease duration, years* | 6.4 (0.0–37.0) | – | – |
| ≤1, n (%) | 84 (23.9) | – | – |
| 1–≤3, n (%) | 22 (6.3) | – | – |
| 3–≤5, n (%) | 38 (10.8) | – | – |
| >5, n (%) | 208 (59.1) | – | – |
| ACR-1997 items, n (%) | |||
| Malar rash | 167 (47.4) | 12 (3.1) | <0.001 |
| Discoid rash | 2 (0.6) | 1 (0.3) | 0.511 |
| Photosensitivity | 61 (17.3) | 8 (2.1) | <0.001 |
| Oral ulcers | 62 (17.6) | 22 (5.7) | <0.001 |
| Arthritis | 182 (51.7) | 124 (32.2) | <0.001 |
| Serositis | 78 (22.2) | 9 (2.3) | <0.001 |
| Renal disorder | 171 (48.6) | 9 (2.3) | <0.001 |
| Neurological disorder | 10 (2.8) | 0 (0.0) | 0.001 |
| Haematological disorder | 297 (84.4) | 167 (43.4) | <0.001 |
| Immunological disorder | 279 (79.3) | 20 (5.2) | <0.001 |
| ANA | 349 (99.1) | 186 (48.3) | <0.001 |
| SLICC-2012 items, n (%) | |||
| Acute cutaneous lupus | 167 (47.4) | 7 (1.8) | <0.001 |
| Chronic cutaneous lupus | 2 (0.6) | 1 (0.3) | 0.511 |
| Oral or nasal ulcers | 62 (17.6) | 22 (5.7) | <0.001 |
| Non-scarring alopecia | 132 (37.5) | 14 (3.6) | <0.001 |
| Synovitis | 182 (51.7) | 124 (32.2) | <0.001 |
| Serositis | 78 (22.2) | 9 (2.3) | <0.001 |
| Renal involvement | 171 (48.6) | 9 (2.3) | <0.001 |
| Neurological involvement | 15 (4.3) | 0 (0.0) | <0.001 |
| Haemolytic anaemia | 100 (28.4) | 13 (3.4) | <0.001 |
| Leucopenia or lymphopenia | 265 (75.3) | 103 (26.8) | <0.001 |
| Thrombocytopenia | 115 (32.7) | 31 (8.1) | <0.001 |
| ANA | 349 (99.1) | 186 (48.3) | <0.001 |
| Anti-dsDNA antibody | 247 (70.2) | 14 (3.6) | <0.001 |
| Anti-Smith antibody | 128 (36.4) | 1 (0.3) | <0.001 |
| Antiphospholipid antibodies | 47 (13.4) | 7 (1.8) | <0.001 |
| Hypocomplementemia | 312 (88.6) | 93 (24.2) | <0.001 |
| Direct Coombs test | 29 (8.2) | 2 (0.5) | <0.001 |
| EULAR/ACR-2019 items, n (%) | |||
| ANA | 349 (99.1) | 186 (48.3) | <0.001 |
| Constitutional fever | 81 (23.0) | 18 (4.7) | <0.001 |
| Haematological | 187 (81.5) | 120 (31.2) | <0.001 |
| Neuropsychiatric | 11 (3.1) | 0 (0.0) | <0.001 |
| Mucocutaneous | 231 (65.6) | 36 (9.4) | <0.001 |
| Serosal | 78 (22.2) | 9 (2.3) | <0.001 |
| Musculoskeletal | 182 (51.7) | 124 (32.2) | <0.001 |
| Renal | 171 (48.6) | 9 (2.3) | <0.001 |
| APL antibodies | 48 (13.6) | 6 (1.6) | <0.001 |
| Hypocomplementemia | 312 (88.6) | 93 (24.2) | <0.001 |
| SLE-specific antibodies | 277 (78.7) | 15 (3.9) | <0.001 |
*Values are presented as median with IQRs.
ACR, American College of Rheumatology; dsDNA, double-stranded DNA; EULAR, European Alliance of Associations for Rheumatology; SLICC, Systemic Lupus International Collaborating Clinics.