Table 1.
Baseline characteristics of patients with early and delayed lupus nephritis
| Variables | Total (n = 171) | Patients with early lupus nephritis (n = 106) | Patients with delayed lupus nephritis (n = 65) | p-value |
|---|---|---|---|---|
| Demographic data | ||||
| Age, years | 36.0 (26.3–46.0) | 36.0 (25.0–48.0) | 36.0 (29.0–44.0) | 0.903 |
| Female sex, n (%) | 153 (89.5) | 91 (85.8) | 62 (95.4) | 0.070 |
| Disease duration, months | n/a | n/a | 52.6 (22.0–118.8) | < 0.001 |
| Follow-up duration, months | 57.1 (17.5–90.8) | 40.9 (14.2–91.3) | 67.6 (27.0–88.9) | 0.119 |
| SLE specific variables | ||||
| Non-renal SLEDAI-2 K | 5.0 (4.0–7.0) | 6.0 (5.0–8.0) | 4.0 (4.0–6.0) | < 0.001 |
| Complement 3, mg/dL | 42.7 (28.7–66.4) | 40.3 (26.2–67.3) | 46.4 (34.9–64.5) | 0.129 |
| Low complement 3, n (%) | 154 (90.1) | 95 (89.6) | 59 (90.8) | 0.808 |
| Complement 4, mg/dL | 5.6 (3.0–12.5) | 5.3 (3.0–12.5) | 6.2 (3.5–12.3) | 0.623 |
| Low complement 4, n (%) | 114 (66.7) | 73 (68.9) | 41 (63.1) | 0.437 |
| Anti-dsDNA (IU/mL) | 218.4 (32.3–379.0) | 160.0 (10.0–379.0) | 300.0 (143.3–379.0) | 0.009 |
| Elevated anti-dsDNA, n (%) | 141 (82.5) | 83 (78.3) | 58 (89.2) | 0.069 |
| Spot urine P/Cr ratio | 2.9 (1.5–6.0) | 3.4 (1.5–6.5) | 2.3 (1.5–4.2) | 0.123 |
| Laboratory data | ||||
| WBC count (/μL) | 4400.0 (3147.5–6145.0) | 3925.0 (3030.5630.0) | 4950.0 (3947.5–6727.5) | 0.018 |
| Platelet count (× 1000/μL) | 203.0 (136.3–247.8) | 200.0 (113.0–240.0) | 213.0 (152.8–253.3) | 0.126 |
| Hemoglobin (g/dL) | 10.4 (9.1–11.7) | 10.2 (8.9–11.5) | 10.9 (9.5–11.9) | 0.189 |
| Lymphocyte count (/μL) | 860.0 (580.0–1227.5) | 840.0 (550.0–1250.0) | 900.0 (610.-1222.5) | 0.999 |
| ESR (mm/hr) | 53.0 (28.5–76.0) | 57.0 (35.0–84.0) | 41.0 (24.8–68.8) | 0.013 |
| CRP (mg/L) | 2.5 (1.0–8.9) | 3.0 (1.0–9.6) | 1.9 (1.0–4.9) | 0.074 |
| Cr (mg/dL) | 0.8 (0.6–1.1) | 0.8 (0.6–1.1) | 0.8 (0.6–1.0) | 0.434 |
| Albumin (g/dL) | 2.9 (2.2–3.4) | 2.6 (2.1–3.3) | 3.2 (2.6–3.4) | 0.002 |
| Clinical manifestations | ||||
| Skin rash | 53 (31.0) | 41 (38.7) | 12 (18.5) | 0.006 |
| Photosensitivity | 13 (7.6) | 10 (9.4) | 3 (4.6) | 0.374 |
| Oral ulcer | 21 (12.3) | 19 (17.9) | 2 (3.1) | 0.004 |
| Arthritis | 10 (5.8) | 8 (7.5) | 2 (3.1) | 0.322 |
| Serositis | 41 (24.0) | 35 (33.0) | 6 (9.2) | < 0.001 |
| Neurologic disorder | 2 (1.2) | 1 (0.9) | 1 (1.5) | 0.726 |
| Hematologic disorder | 152 (88.9) | 95 (89.6) | 57 (87.7) | 0.698 |
| Immunologic disorder | 159 (93.0) | 100 (94.3) | 59 (90.8) | 0.376 |
| Comorbidities | ||||
| Hypertension | 33 (19.3) | 11 (10.4) | 22 (33.8) | < 0.001 |
| Diabetes mellitus | 4 (2.3) | 3 (2.8) | 1 (1.5) | 0.999 |
| Dyslipidemia | 2 (1.2) | 2 (1.9) | 0 (0.0) | 0.526 |
Values are expressed as median (interquartile range) or n (%)
n/a not applicable, SLEDAI-2 K systemic lupus erythematosus disease activity index-2000, P/Cr protein/creatinine, WBC white blood cell, ESR erythrocyte sedimentation rate, CRP C-reactive protein, Cr creatinine