Table 1.
Clinical and histologic characteristics of the patients at baseline and during the follow-up period according to C4d staining
| Variable | Total (N=283) | C4d-Positive (n=109) | C4d-Negative (n=174) | P Value |
|---|---|---|---|---|
| Mean age (yr) | 39.1±17.2 | 38.6±15.0 | 39.4±18.5 | 0.72 |
| Male sex | 208 (73.8) | 81 (74.3) | 127 (73.4) | 0.89 |
| Macroscopic hematuria | 129 (45.6) | 43 (39.4) | 86 (49.4) | 0.06 |
| Hypertension | 155 (55.2) | 78 (71.6) | 77 (44.8) | <0.001 |
| eGFR (ml/min per 1.73 m2) | 67.7±35.9 | 58.9±34.1 | 73.2±36.0 | 0.001 |
| Stage (eGFR in ml/min/1.73 m2) | 0.02 | |||
| 1 (≥90) | 84 (29.7) | 22 (20.2) | 62 (35.8) | |
| 2 (60–89) | 69 (24.4) | 26 (23.9) | 43 (24.9) | |
| 3 (30–59) | 82 (29.0) | 38 (34.9) | 44 (25.4) | |
| 4 (15–29) | 29 (10.2) | 16 (14.7) | 13 (7.5) | |
| 5 (<15) | 18 (6.4) | 7 (6.4) | 11 (6.4) | |
| Median urinary protein excretion (g/d) | 1.9 (1.0–3.0) | 2.2 (1.4–3.6) | 1.7 (1.0–2.6) | <0.001 |
| Urinary protein excretion (g/d) | 0.01 | |||
| <0.30 | 13 (4.6) | 1 (0.9) | 12 (6.9) | |
| 0.30–0.99 | 42 (14.8) | 14 (12.8) | 28 (16.1) | |
| 1–2.99 | 150 (53.0) | 53 (48.6) | 97 (55.7) | |
| ≥3.0 | 78 (27.6) | 41 (37.6) | 37 (21.3) | |
| Proteinuria≥1 g/d | 228 (80.6) | 94 (86.2) | 134 (77.0) | 0.03 |
| Oxford classification | ||||
| M1 | 183 (64.7) | 77 (73.3) | 106 (66.3) | 0.13 |
| E1 | 62 (21.9) | 28 (25.7) | 34 (19.5) | 0.14 |
| S1 | 57 (20.1) | 35 (32.4) | 22 (12.6) | <0.001 |
| Tubular atrophy/interstitial fibrosis (%) | <0.001 | |||
| T0 (<25) | 112 (39.6) | 15 (13.8) | 97 (55.7) | |
| T1 (25–50) | 90 (31.8) | 41 (37.6) | 49 (28.2) | |
| T2 (>50) | 81 (28.6) | 53 (48.6) | 28 (16.1) | |
| Use of ACEI/ARB | 225 (79.5) | 90 (89.1) | 135 (87.1) | 0.39 |
| Use of prednisone | 100 (35.3) | 35 (33.7) | 65 (38.2) | 0.51 |
| Any other immunosuppressive treatmenta | 60 (21.2) | 23 (23.2) | 37 (23.9) | >0.99 |
| Median follow-up period (yr) | 6.0 (3.0–11.7) | 5.3 (2.9–8.3) | 6.6 (3.0–13.1) | 0.03 |
| Evolution to ESRD in the follow-upb | 58 (20.5) | 41 (37.6) | 17 (9.8) | <0.001 |
For quantitative variables, values are expressed as the mean±SD or the median (interquartile range) as appropriate. For qualitative variables, values are expressed as n (%). M, mesangial hypercellularity; E, endocapillary hypercellularity; S, segmental glomerulosclerosis; T, tubular atrophy/interstitial fibrosis; ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker.
a
Immunosuppressive agents include cyclophosphamide, mycophenolate, or others.
b
ESRD: chronic dialysis or renal transplantation.