Table 1 Baseline characteristics of the patients
Baseline variables | Early-onset LN (N = 113) | Late-onset LN (N = 71) | p value | Baseline variables | Early-onset LN (N = 113) | Late-onset LN (N = 71) | p value | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Median | IQR | Median | IQR | Median | IQR | Median | IQR | ||||
Age at SLE onset, years | 32 | (21–45) | 24 | (16–31) | < 0.001* | CH50 (mg/dl) | 16.8 | (10.4–30.0) | 18.9 | (14.5–31.2) | 0.016* |
Age at LN onset, years | 32 | (22–46) | 35 | (29–44) | 0.065 | C3 (mg/dl) | 41.2 | (28.9–63.4) | 56.5 | (40.9–72.5) | 0.001* |
Sex (% female) | 92/113(81.4) | 64/71(90.1) | 0.141 | C4 (mg/dl) | 8.0 | (4.3–13.1) | 10.0 | (6.1–16.4) | 0.069 | ||
SLE duration, months | 2 | (0–10) | 125 | (101–197) | < 0.001* | Comorbidities of SS (%) | 15/113 (13.3) | 7/71 (9.9) | 0.642 | ||
Proteinuria, g/gCr | 1.4 | (0.6–3.8) | 2.1 | (1.0–3.4) | 0.199 | Comorbidities of APS (%) | 13/113 (11.5) | 5/71 (7.0) | 0.446 | ||
White blood cell count, /μl | 4700 | (3720–6800) | 5800 | (4560–7725) | 0.004* | ISN/RPS III or IV (%) | 54/113 (47.8) | 45/71 (63.4) | 0.048* | ||
Lymphocyte count, /μl | 880 | (554–1491) | 918 | (617–1400) | 0.998 | ISN/RPS V (%) | 24/113 (21.2) | 17/71 (23.9) | 0.717 | ||
Hemoglobin, g/dl | 11.0 | (9.8–12.2) | 11.5 | (10.4–13.1) | 0.066 | Index of activity (0–24) | 5 | (3–7) | 6 | (4–8) | 0.056 |
Platelet counts, ×104/μl | 20.7 | (14.0–26.1) | 22.2 | (17.0–27.7) | 0.174 | Index of chronicity (0–12) | 2 | (0–2) | 3 | (2–4) | < 0.001* |
Albumin, g/dl | 3.2 | (2.5–3.8) | 3.2 | (2.8–3.8) | 0.324 | mPSL pulse (%) | 60/109 (55.1) | 42/70 (60.0) | 0.539 | ||
BUN, mg/dl | 14.2 | (11.0–20.0) | 15.5 | (12.0–21.3) | 0.504 | TAC (%) | 30/109 (27.5) | 28/70 (40.0) | 0.102 | ||
Cr, mg/dl | 0.7 | (0.6–1.0) | 0.7 | (0.6–0.9) | 0.906 | CyA (%) | 11/109 (10.1) | 9/70 (12.9) | 0.630 | ||
eGFR, ml/min/1.73 m2 | 80.6 | (58.0–102.6) | 78.8 | (57.7–97.6) | 0.560 | AZP (%) | 2/109 (1.8) | 2/70 (2.9) | 0.645 | ||
ANA | 640 | (175–1280) | 320 | (80–640) | < 0.001* | MZR (%) | 28/109 (25.7) | 18/70 (25.7) | 1.000 | ||
Anti-ds-DNA antibodies, U/ml | 50.8 | (12.1–300.0) | 20.8 | (5.1–71.7) | < 0.001* | IVCY (%) | 24/109 (22.0) | 17/70 (24.3) | 0.720 | ||
Anti-RNP antibodies, U/ml | 8.7 | (4.2–98.5) | 8.8 | (2.4–86.2) | 0.403 | MMF (%) | 4/109 (3.7) | 5/70 (7.1) | 0.316 | ||
Anti-Sm antibodies, U/ml | 8.7 | (2.3–88.2) | 4.4 | (1.0–28.9) | 0.095 | PE (%) | 9/109 (8.3) | 5/70 (7.1) | 1.000 | ||
IgG, mg/dl | 1750 | (1327–2190) | 1150 | (801–1482) | < 0.001* | Hypertension (%) | 43/110 (39.1) | 27/68 (39.7) | 1.000 | ||
IgA, mg/dl | 271 | (196–369) | 274 | (188–369) | 0.371 | Biopsy before 2002 | 52/113 (46.0) | 28/71 (39.4) | 0.446 | ||
IgM, mg/dl | 114.0 | (75.2–175.0) | 27.1 | (45.8–142.3) | < 0.001* |  |  |  |  |  |  |