Table 1.
Clinical characteristics of the clusters according to the laboratory findings at the time of SLE diagnosis.
| Cluster 1 | Cluster 2 | Cluster 3 | p-Value a | ||||
|---|---|---|---|---|---|---|---|
| (n = 131) | (n = 183) | (n = 75) | Overall | 1 vs. 2 | 1 vs. 3 | 2 vs. 3 | |
| Diagnostic age, years | 31.2 ± 13.2 | 35.6 ± 12.6 | 36.8 ± 12.3 | <0.001 | 0.044 | <0.001 | 0.752 |
| Male: female, n (%) | 10 (7.6):121 (92.4) | 15 (8.2):168 (91.8) | 4 (5.3):71 (94.7) | 0.819 | 1.000 | 0.775 | 0.601 |
| Duration, month b | 117.8 ± 48.5 | 126.0 ± 40.6 | 138.4 ± 146.8 | 0.169 | 0.608 | 0.144 | 0.455 |
| WBC count,/µL | 5623.9 ± 3157.4 | 6111.9 ± 2304.6 | 4673.1 ± 1877.5 | <0.001 | 0.219 | 0.029 | <0.001 |
| Lymphocyte count,/µL | 1214.3 ± 628.1 | 1765.5 ± 683.0 | 1171.2 ± 395.7 | <0.001 | <0.001 | 0.881 | <0.001 |
| Hemoglobin,/µL | 11.5 ± 1.8 | 12.5 ± 1.6 | 12.3 ± 1.1 | <0.001 | <0.001 | 0.001 | 0.581 |
| Platelet count, ×103/µL | 208.1 ± 76.7 | 238.9 ± 88 | 225.7 ± 66.7 | 0.004 | 0.003 | 0.288 | 0.452 |
| ESR, mm/h | 30.4 ± 26.5 | 16.8 ± 17.9 | 26.7 ± 20.1 | <0.001 | <0.001 | 0.454 | 0.003 |
| CRP, mg/dL | 1.1 ± 3 | 0.5 ± 1.8 | 0.7 ± 2 | 0.097 | 0.078 | 0.554 | 0.756 |
| Complement 3, mg/dL | 71.8 ± 29.4 | 112.7 ± 27.3 | 110.5 ± 21.7 | <0.001 | <0.001 | <0.001 | 0.820 |
| Complement 4, mg/dL | 13 ± 7.5 | 25 ± 9.7 | 27.5 ± 8.6 | <0.001 | <0.001 | <0.001 | 0.100 |
| Anti-dsDNA antibody, IU/mL | 47.8 ± 38.5 | 7.2 ± 10.3 | 7.5 ± 6.8 | <0.001 | <0.001 | <0.001 | 0.996 |
| ANA titer | 1715.1 ± 1135.3 | 463.8 ± 641.6 | 2474.7 ± 731.5 | <0.001 | <0.001 | <0.001 | <0.001 |
| Homogenous (AC-1), n (%) | 46 (35.4) | 64 (35) | 11 (14.7) | 0.002 | 1.000 | 0.001 | 0.001 |
| Nucleolar (AC-8,9,10), n (%) | 0 (0) | 15 (8.2) | 1 (1.3) | <0.001 | <0.001 | 0.366 | 0.045 |
| Speckled (AC-4,5), n (%) | 58 (44.6) | 56 (30.6) | 54 (72) | <0.001 | 0.012 | <0.001 | <0.001 |
| Cytoplasmic (AC-15 to AC-23), n (%) | 3 (2.3) | 22 (12) | 1 (1.3) | <0.001 | 0.001 | 1.000 | 0.004 |
| Mixed, n (%) | 21 (16.2) | 26 (14.2) | 8 (10.7) | 0.575 | 0.634 | 0.306 | 0.545 |
ANA, anti-nuclear antibody; CRP, C-reactive protein; dsDNA, double-stranded DNA; ESR, erythrocyte sedimentation rate; NA, not available; SLE, systemic lupus erythematosus; WBC, white blood cell. a p-Values were calculated using ANOVA with Tukey’s and Fisher’s exact tests. b Duration was defined as the period between the initial test and cumulative data collection. Continuous variables are presented as means ± standard deviations.