The characteristics of patients in SLE and control groups.
| Characteristics | SLE Group, n = 262 | Control Group, n = 174 | P |
|---|---|---|---|
| Sex, female | 212 (80.9) | 106 (60.9) | < 0.001 |
| Age at disease onset, months, median (min–max) | 151.5 (4–215) | 108 (1–204) | < 0.001 |
| Age at diagnosis, months, median (min–max) | 160 (7–215) | 112 (4–204) | < 0.001 |
| Comorbid diseases | 46 (17.6) | 2 (1.1) | < 0.001 |
| Fever (> 38.3°C) | 66 (25.2) | 29 (16.7) | 0.035 |
| Pleural effusion | 19 (7.3) | 4 (2.3) | 0.023 |
| Pleuritis | 6 (2.3) | 0 (0) | 0.085* |
| Pericardial effusion | 15 (5.7) | 0 (0) | 0.001 |
| Pericarditis | 13 (5) | 0 (0) | 0.003 |
| Joint involvement | 133 (50.8) | 72 (41.4) | 0.055 |
| Nonscarring alopecia | 27 (10.3) | 0 (0) | < 0.001 |
| Oral ulcers | 71 (27.1) | 23 (13.2) | 0.001 |
| Nasal ulcers | 2 (0.8) | 0 (0) | 0.51* |
| Malar rash | 128 (48.9) | 13 (7.5) | < 0.001 |
| Discoid rash | 10 (3.8) | 1 (0.6) | 0.056* |
| Photosensitivity | 70 (26.7) | 8 (4.6) | < 0.001 |
| Generalized maculopapular rash | 24 (9.2) | 11 (6.3) | 0.28 |
| Annular papulosquamous cutaneous eruption | 5 (1.9) | 1 (0.6) | 0.40* |
| Bullous lupus | 2 (0.8) | 0 (0) | 0.51* |
| Hypertrophic verrucous lupus | 2 (0.8) | 0 (0) | 0.51* |
| Lupus panniculitis (profundus) | 3 (1.1) | 2 (1.1) | > 0.99* |
| Chilblain lupus | 3 (1.1) | 0 (0) | 0.27* |
| Discoid lupus/lichen planus overlap | 2 (0.8) | 0 (0) | 0.51* |
| Delirium | 2 (0.8) | 1 (0.6) | > 0.99* |
| Psychosis | 4 (1.5) | 0 (0) | 0.15* |
| Seizure | 15 (5.7) | 2 (1.1) | 0.02 |
| Focal neurologic defect | 4 (1.5) | 4 (2.3) | 0.71* |
| Peripheral neuropathy | 5 (1.9) | 3 (1.7) | > 0.99* |
| Cranial neuropathy | 1 (0.4) | 3 (1.7) | 0.30* |
| Acute confusional state | 5 (1.9) | 1 (0.6) | 0.40* |
| Coma | 1 (0.4) | 0 (0) | > 0.99* |
| Leukopenia (< 4000/mm3) | 60 (22.9) | 6 (3.4) | < 0.001 |
| Lymphopenia (< 1000/mm3) | 32 (12.2) | 3 (1.7) | < 0.001 |
| Lymphopenia (< 1500/mm3) | 66 (25.2) | 6 (3.4) | < 0.001 |
| Thrombocytopenia (< 100,000/mm3) | 67 (25.6) | 16 (9.2) | < 0.001 |
| Evidence of hemolysis | 65 (24.8) | 7 (4) | < 0.001 |
| Hematologic involvement | 145 (55.3) | 24 (13.8) | < 0.001 |
| Low C3 | 159 (60.7) | 24/133 (18) | < 0.001 |
| Low C4 | 182 (69.5) | 33/131 (25.2) | < 0.001 |
| Low CH50 | 6/55 (10.9) | 1/6 (16.6) | 0.53* |
| Proteinuria | 69 (26.3) | 14 (8) | < 0.001 |
| Urinary casts | 34 (14.9) | 9 (5.2) | 0.002 |
| ANA positivity (≥ 1/80) | 259 (98.9) | 127 (73) | < 0.001 |
| Anti-dsDNA | 164 (62.6) | 7/144 (4.8) | < 0.001 |
| Anti-Sm | 37/203 (18.2) | 4/70 (5.7) | 0.01 |
| Anticardiolipin antibodies | 53/235 (22.5) | 2/83 (2.4) | < 0.001 |
| Anti-β2-GPI | 29/153 (18.9) | 1/44 (2.3) | 0.007 |
| Lupus anticoagulant | 27/160 (16.8) | 1/41 (2.4) | 0.02 |
| Direct Coombs | 94/241 (39) | 2/20 (10) | 0.01 |
| False RPR positivity | 6/34 (17.6) | Not checked | – |
| Biopsy-proven LN | 97 (37) | 0 (0) | < 0.001 |
| SLE (ACR 1997 criteria) | 180 (68.7) | 9 (5.2) | < 0.001 |
| SLE (SLICC 2012 criteria) | 250 (95.4) | 18 (10.3) | < 0.001 |
| SLE (EULAR/ACR 2019 criteria) | 240 (91.6) | 20 (11.5) | < 0.001 |
Values are expressed as n (%) unless stated otherwise.
↵*These comparisons were done utilizing the Fisher exact test while chi-square test was used for the rest of the comparisons. ACR: American College of Rheumatology; ANA: antinuclear antibody; anti-β2-GPI: anti-β2-glycoprotein I; EULAR: European League Against Rheumatism; LN: lupus nephritis; RPR: rapid plasma reagin; SLE: systemic lupus erythematosus; SLICC: Systemic Lupus International Collaborating Clinics.