Table 3.
Demographic, clinical, and histologic findings of patients with very low levels of proteinuria
| Cohort characteristics | Proteinuria <0.25 g/d (n = 25) | Both proteinuria <0.25 g/d and serum creatinine ≥1 mg/dl (n = 5) |
Both proteinuria <0.25 g/d and serum creatinine <1 mg/dl (n = 20) | P valuea |
|---|---|---|---|---|
| Female, % | 21 (84) | 5 (100) | 16 (80) | NS |
| Age, yr | 32 (18–65) | 24 (22–42) | 32 (18–65) | NS |
| Duration of lupus, mo | 12 (2–56) | 12 (4–44) | 5 (2–56) | NS |
| Glomerular hematuria present | 25 (100) | 5 (100) | 20 (100) | NS |
| Proteinuria, g/d | 0.05 (0.05–0.23) | 0.20 (0.05–0.23) | 0.05 (0.05–0.22) | NS |
| Serum creatinine, mg/dl | 0.70 (0.5–1.1) | 1.0 (1.0–1.1) | 0.63 (0.5–0.9) | 0.0008 |
| ANA-positive | 25 (100) | 5 (100) | 20 (100) | NS |
| Anti-dsDNA–positive | 19 (76) | 4 (80) | 15 (75) | NS |
| C3, mg/dl | 64 (15–174) | 44 (15–79) | 87.5 (20–174) | 0.032 |
| C4, mg/dl | 12 (1–43) | 3 (1–14) | 12.5 (1–43) | NS |
| Activity index | 5 (0–10) | 6 (6–7) | 4 (0–10) | NS |
| Chronicity index | 2 (0–4) | 2 (2–3) | 1 (0–4) | NS |
| ISN/RPS class II | 5 (20) | 0 (0) | 5 (25) | NS |
| ISN/RPS class III | 6 (24) | 1 (20) | 5 (25) | |
| ISN/RPS class III+V | 1 (4) | 0 (0) | 1 (5) | |
| ISN/RPS class IV | 12 (48) | 4 (80) | 8 (40) | |
| ISN/RPS class V | 1 (4) | 0 (0) | 1 (5) |
ANA, anti-nuclear antibody; anti-dsDNA, anti–double-stranded DNA antibody; C3, complement C3; C4, complement C4; ISN/RPS, International Society of Neurology/Renal Pathology Society; NS, not significant.
Data are expressed as number of patients (% of group) or as median (range).
a
Compares patients with proteinuria <0.25 g/d with a serum creatinine level of ≥1 mg/dl and those with proteinuria <0.25 g/d and a serum creatinine of <1mg/dl. χ2, Mann–Whitney, and Fisher exact test used where appropriate.