Table 3.
Baseline characteristics for progressors and nonprogressors classified according to initial excretion of β2-microglobulin ≥1.0 μg/min
| Progressors |
Nonprogressorsa |
Pb | |||
|---|---|---|---|---|---|
| β2m ≥ 1.0 | β2m < 1.0 | β2m < 1.0 | β2m ≥ 1.0 | ||
| Number of subjects (% male subjects) | 44 (75) | 16 (62) | 52 (65) | 17 (65) | 0.69 |
| Age at time of biopsy (years)c | 57 (47 to 64) | 49 (44 to 58) | 49 (38 to 60) | 56 (51 to 64) | 0.02 |
| Time between biopsy and urine analysis (months) | 2 (1 to 4) | 2 (0 to 2) | 1 (1 to 4) | 2 (1 to 4) | 0.88 |
| Survival time (months) | 11 (6 to 25) | 16 (7 to 25) | 53 (28 to 84) | 41 (24 to 54) | |
| MAP (mmHg) | 100 (89 to 112) | 94 (81 to 105) | 93 (86 to 104) | 99 (92 to 104) | 0.16 |
| Laboratory | |||||
| serum creatinine (μmol/L) | 110 (97 to 119) | 90 (68 to 95) | 80 (70 to 87) | 86 (82 to 91) | <0.001 |
| serum albumin (g/L) | 20 (17 to 24) | 23 (18 to 26) | 27 (23 to 31) | 22 (17 to 25) | <0.001 |
| serum cholesterol (mmol/L) | 8.4 (7.0 to 9.8) | 8.5 (5.7 to 9.3) | 6.5 (5.5 to 7.7) | 6.1 (5.3 to 7.3) | 0.004 |
| eGFRMDRD4 (ml/min per 1.73 m2) | 58 (53 to 67) | 75 (65 to 97) | 85 (78 to 93) | 75 (67 to 80) | <0.001 |
| Urine samples | |||||
| proteinuria (g/10 mmol creatinine) | 10.7 (9.3 to 12.7) | 5.5 (4.8 to 8.7) | 6.2 (4.7 to 8.5) | 9.1 (5.9 to 11.0) | <0.001 |
| β2-microglobulin (μg/min) | 7.8 (2.3 to 13.8) | 0.3 (0.1 to 0.5) | 0.1 (0.2 to 0.4) | 2.6 (1.3 to 7.7) | |
| α1-microglobulin (μg/min) | 106 (61 to 131) | 31 (20 to 44) | 22 (12 to 37) | 50 (39 to 83) | |
| IgG (mg/24 h) | 511 (356 to 776) | 157 (74 to 217) | 119 (62 to 219) | 351 (158 to 607) | |
| Selectivity index>d | 0.27 ± 0.08 | 0.11 ± 0.05 | 0.15 ± 0.07 | 0.21 ± 0.08 | <0.001 |
| Medication (%) | |||||
| ACEi/ARB use at time of biopsy | 36 | 20 | 16 | 6 | 0.03 |
| ACEi/ARB use during follow-up | 100 | 100 | 98 | 100 | 0.68 |
| statin use at time of biopsy | 20 | 7 | 10 | 6 | 0.26 |
| statin use during follow-up | 93 | 93 | 84 | 94 | 0.43 |
| Outcomes | |||||
| progression (%) | 100 | 100 | 0 | 0 | |
| 50% rise in serum creatinine (n) | 18 | 12 | |||
| 25% rise and serum creatinine >135 μmol/L (n) | 24 | 0 | |||
| clinical progression (n) | 2 | 4 | |||
| Spontaneous remission (%) | |||||
| partial remission: < 2.0 g/10 mmol | 0 | 0 | 90 | 82 | |
| partial remission: <3.5 g/10 mmol and ≥50% reduction | 0 | 0 | 94 | 82 | |
| complete remission | 0 | 0 | 40 | 29 | |
β2-microglobulin, β2m; MAP, mean arterial pressure; eGFRMDRD4, estimated GFR calculated with the Modification of Diet in Renal Disease formula; ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker.
a
Misclassified progressors are those patients who did show progression but had uβ2m < 1.0 μg/min.
b
ANOVA was used to compare continuous data between the four groups and chi-squared tests to compare medication use and gender.
c
Values are medians with interquartile range in parentheses.
d
Values are mean ± SD.