Table 2.
Clinical and histologic characteristics of 203 patients with lupus nephritis at kidney biopsy
| Characteristics | All Patients (n=203) | Patients Who Developed KFI (n=39) | Patients Who Did Not Develop KFI (n=164) | P Value |
|---|---|---|---|---|
| Months from SLE to lupus nephritis | 8.06 (0–61.6) | 3.9 (0–49.4) | 8.5 (0–70) | 0.04 |
| Months from renal manifestations to kidney biopsy | 3.12 (0.92–13.01) | 7.9 (1.6–32.6) | 2.6 (0.7–10.7) | 0.04a |
| Female/male, n | 177/26 | 33/6 | 144/20 | 0.59 |
| White/other race or ethnicity, n | 184/19 | 36/3 | 148/16 | 0.69 |
| Age at renal biopsy, yr | 32.4 (24.15–42.52) | 31.3 (24.1–39) | 33.9/24.5–47.6) | 0.35 |
| Serum creatinine, mg/dl | 0.9 (0.7–1.4) | 1.5 (1.1–2.4) | 0.8 (0.7–1.2) | <0.001a |
| Creatinine clearance, ml/min | 80.45 (51.6–110.1) | 47 (30.15–74.9) | 88.5 (68.1–112.4) | <0.001a |
| Proteinuria, g/d | 3 (1.9–5) | 4.2 (3–5.6) | 2.9 (1.7–4.9) | 0.009a |
| Arterial hypertension, n (%) | 102 (50) | 32 (82) | 70 (43) | <0.001a |
| ACE inhibitors, n (%) | 160 (79) | 34 (87) | 126 (77) | 0.16 |
| Urinary erythrocytes number per HPF | 11 (3–40) | 15 (4.3–40) | 10 (3–40) | 0.51 |
| Serum C3, mg/dl, (normal values >90 mg/dl) | 59 (46–79) | 56 (47.5–81) | 60 (46–78) | 0.97 |
| Serum C4, mg/dl, (normal values 10–40 mg/dl) | 10 (6–15) | 11 (5–18.3) | 10 (6–15) | 0.65 |
| Hematocrit, % | 34 (29–38) | 30 (28–37) | 34 (30–38) | 0.10 |
| Serum albumin, g/dl | 2.9 (2.4–3.5) | 2.6 (2.3–3.4) | 3 (2.5–3.5) | 0.10 |
| White blood cells, mmc | 5700 (3900–7540) | 6225 (5000–8450) | 5600 (3850–7500) | 0.50 |
| Platelets, µl | 239 (109–304) | 219,500 (175,250–303,750) | 246,000 (183,250–299,750) | 0.31 |
| Ab anti-dsDNA positivity, n (%) | 172 (88) | 32 (87) | 140 (88) | 0.61 |
| Ab anti-phospholipid, n (%) | 44 (23) | 7 (19) | 37 (24) | 0.53 |
| ENA positivity, % e | ||||
| Anti-SM | 23 | 19 | 24 | 0.79 |
| Anti-SSA | 36 | 32 | 36 | 0.89 |
| Anti-SSB | 15 | 16 | 15 | 0.97 |
| Anti-RNP | 28 | 24 | 29 | 0.63 |
| Clinical manifestations, % | ||||
| Skin | 62 | 63 | 61 | 0.92 |
| Arthralgias | 74 | 74 | 74 | 0.99 |
| Serositis | 25 | 33 | 23 | 0.35 |
| Cerebritis | 5 | 10 | 4 | 0.24 |
| Fever | 53 | 56 | 52 | 0.83 |
| Lymphadenopathy | 13 | 13 | 14 | 0.90 |
| Therapy | ||||
| Methylprednisolone pulses, n (%) | 169 (84) | 31 (82) | 138 (85) | 0.48 |
| IST induction, n (%) | 174 (87) | 32 (84) | 142 (88) | 0.45 |
| No-IST/CY/MMF/AZA/CsA/others, n | 25/99/43/19/4/9 | 6/18/3/6/0/5 | 19/81/40/13/4/4 | |
| Maintenance, n (%) | 120 (61) | 15 (40) | 105 (66) | 0.002a |
| No-IST/MMF/AZA/CsA/others, n | 77/71/38/10/1 | 23/9/5/1/0 | 54/62/33/9/1 | |
| Histologic characteristics | ||||
| Histologic class, n (%) | ||||
| II | 2 (0.9) | 0 | 2 (1) | 0.53 |
| III | 45 (22) | 5 (13) | 40 (24) | 0.12 |
| IV | 108 (53) | 26 (67) | 82 (50) | 0.06 |
| V | 48 (24) | 8 (21) | 40 (24) | 0.61 |
| Activity index score, n (%) | 6 (2–9) | 6 (2–9) | 6 (2–9) | 0.80 |
| Activity index >6 | 88 (43) | 17 (44) | 71 (43) | 0.99 |
| Endocapillary hypercellularityb | 133 (66) | 26 (67) | 107 (65) | 0.94 |
| Neutrophil infiltrationb | 153 (75) | 29 (74) | 124 (76) | 0.89 |
| Hyaline deposits/wire loopsb | 105 (52) | 25 (64) | 80 (49) | 0.09 |
| Cellular/fibrocellular crescentsc | 40 (20) | 9 (23) | 31 (19) | 0.56 |
| Fibrinoid necrosis/karyorrhexisc | 71 (35) | 8 (21) | 63 (38) | 0.04a |
| Interstitial inflammationb | 101 (50) | 25 (64) | 76 (46) | 0.05a |
| Chronicity index score, n (%) | 2 (1–3) | 3 (1–7) | 1 (1–3) | <0.001a |
| Chronicity index >2 | 70 (35) | 23 (59) | 47 (29) | <0.001a |
| Glomerulosclerosisc | 28 (14) | 14 (36) | 14 (9) | <0.001a |
| Fibrous crescentsc | 27 (13) | 13 (33) | 14 (9) | <0.001a |
| Tubular atrophyc | 14 (7) | 9 (23) | 5 (3) | <0.001a |
| Interstitial fibrosisc | 20 (10) | 13 (33) | 7 (4) | <0.001a |
| Neutrophil infiltration/karyorrhexisb | 152 (75) | 29 (74) | 123 (75) | 0.97 |
| Fibrinoid necrosisc | 45 (22) | 4 (10) | 41 (25) | 0.05a |
| Extraglomerular immune deposits, n positive (%) d | 95 (47) | 25 (64) | 70 (15) | 0.02a |
| Tubular basement deposits | 71 (35) | 16 (41) | 55 (34) | 0.38 |
| Interstitial capillary wall deposits | 18 (9) | 5 (13) | 13 (8) | 0.33 |
| Vascular deposits | 45 (22) | 15 (39) | 30 (18) | 0.006a |
If not otherwise specified, data are expressed as medians with interquartile ranges. KFI, kidney function impairment; ACE, angiotensin-converting enzyme; HPF, high powered field; Ab, antibody; dsDNA, double-stranded DNA; ENA, extractable nuclear antigen; Anti-SM, anti-Smith autoantibodies; Anti-SSA, anti–Sjögren's-syndrome-related antigen A autoantibodies; Anti-SSB anti–Sjögren's-syndrome-related antigen B autoantibodies, Anti-RNP, anti-Ribonucleoprotein autoantibodies; IST, immunosuppressive therapy; CY, cyclophosphamide; MMF, mycophenolate mofetil; AZA, azathioprine; CsA, cyclosporine.
P≤0.05; P values are evaluated with t test or nonparametric Wilcoxon test for independent samples and with chi-squared test between qualitative or dichotomized variables.
Variables were categorized as 0 versus 1+2+3, where 0, represents absent; 1, in <25% of glomeruli, or of interstitial or of tubular cortex; 2, from 25% to 50% of glomeruli, or of interstitial or of tubular cortex; 3, >50% of glomeruli, or of interstitial or of tubular cortex.
All of these variables were categorized as 0+1 versus 2+3.
Patients with extraglomerular immune deposits (%).
Data were not available in 34 patients.