Table 1 Characteristics of IMN patients by serum factor Bb tertiles at biopsy. IMN, idiopathic membranous nephropathy; MAP, mean arterial pressure; PLA2R Ab, M-type phospholipase A2 receptor antibody; eGFR, estimated glomerular filtration rate; TA/IF, tubular atrophy/interstitial fibrosis; ESRD, end stage renal disease. Values were presented as number (percent) or median (25th percentile-75th percentile). Kruskal-Wallis test or chi-square test was applied to compare the values among groups. The last column represents the P-values from comparisons among groups of the lowest, middle and highest tertiles.
Variables | Overall | Serum factor Bb (103 ng/mL, range) | |||
|---|---|---|---|---|---|
Lowest tertile < 1.21 | Middle tertile 1.21–3.68 | Highest tertile > 3.68 | P | ||
Baseline | |||||
No. of patients | 449 | 149 | 150 | 150 | |
Factor Bb levels (103 ng/mL) | 2.32 (0.79, 4.30) | 0.43 (0.35, 0.79) | 2.31 (1.72, 3.11) | 5.52 (4.27, 9.87) | < 0.001 |
Age (years) | 49 (39, 59) | 49 (35, 59) | 49 (40, 60) | 48 (40, 57) | 0.391 |
Sex (men, %) | 252 (56.1) | 84 (56.4) | 73 (48.7) | 95 (63.3) | 0.038 |
MAP (mmHg) | 100 (94, 109) | 100 (93, 109) | 100 (94, 107) | 99 (93, 109) | 0.622 |
PLA2R Ab (RU/mL) | 103.5 (25.3, 236.4) | 60.2 (8.0, 110.2) | 98.7 (13.7, 251.4) | 200.0 (87.2, 333.5) | < 0.001 |
Albumin (g/L) | 25.0 (21.5, 31.0) | 28.4 (23.1, 32.5) | 25.7 (21.9, 31.8) | 23.1 (20.1, 27.1) | < 0.001 |
eGFR (mL/min/1.73m2) | 105 (95, 114) | 107 (96, 118) | 106 (96, 113) | 104 (94, 111) | 0.016 |
Proteinuria (g/24 h) | 4.55 (2.52, 8.22) | 3.34 (1.89, 5.52) | 4.53 (1.98, 8.61) | 6.33 (4.10, 9.62) | < 0.001 |
Churg’s stages | |||||
MN-I, n (%) | 226 (50.3) | 89 (59.7) | 64 (42.7) | 73 (48.7) | 0.011 |
MN-II, n (%) | 132 (29.4) | 33 (22.1) | 46 (30.7) | 53 (35.3) | 0.040 |
MN-III, n (%) | 91 (20.3) | 27 (18.1) | 40 (26.7) | 24 (16.0) | 0.052 |
The intensity of TA/IF | |||||
Scores 0–1, n (%) | 216 (48.1) | 91 (61.1) | 79 (52.7) | 46 (30.7) | < 0.001 |
Score 2, n (%) | 127 (28.3) | 44 (29.5) | 39 (26.0) | 44 (29.3) | 0.748 |
Score 3, n (%) | 106 (23.6) | 14 (9.4) | 32 (21.3) | 60 (40.0) | < 0.001 |
Follow-up | |||||
Follow-up interval (months) | 46 (29, 63) | 54 (31, 66) | 43 (27, 62) | 45 (28, 61) | 0.036 |
Biopsy to initial immunosuppressive therapy interval (months) | 7 (5, 9) | 8 (6, 9) | 6 (5, 9) | 6 (5, 8) | 0.051 |
Treated with immunosuppressive agents, n (%) | 305 (67.9) | 85 (57.0) | 96 (64.0) | 124 (82.7) | < 0.001 |
NO | 144 (32.1) | 64 (43.0) | 54 (36.0) | 26 (17.3) | < 0.001 |
CNI | 120 (26.7) | 37 (24.8) | 51 (34.0) | 32 (21.3) | 0.038 |
CTX | 78 (17.4) | 19 (12.8) | 25 (16.7) | 34 (22.7) | 0.074 |
Others | 107 (23.8) | 29 (19.4) | 20 (13.3) | 58 (38.7) | < 0.001 |
Outcome | |||||
Composite end point, n (%) | 139 (31.0) | 14 (9.4) | 48 (32.0) | 77 (51.3) | < 0.001 |
ESRD, n (%) | 17 (3.8) | 2 (1.3) | 4 (2.7) | 11 (7.3) | 0.017 |
