Table 1.
Comparison of demographics, disease phenotype, and induction therapy
| Caucasian (N = 597, 89%) | AA (N = 75, 11%) | p-Valuea | |
|---|---|---|---|
| Age (years) at diagnosis, mean ± SD | 57 ± 18 | 52 ± 20 | 0.051 |
| Females | 268 (45%) | 40 (53%) | 0.18 |
| ANCA typeb | 0.0114 | ||
| Both | 2 (0.34%) | 0 (0%) | |
| PR3/c-ANCA | 260 (44%) | 19 (25%) | |
| MPO/p-ANCA | 321 (54%) | 53 (71%) | |
| ANCA neg. | 13 (2%) | 3 (4%) | |
| Vasculitis type | 0.17 | ||
| EGPA | 2 (0.34%) | 1 (1%) | |
| GPA | 153 (26%) | 19 (25%) | |
| Renal limited | 122 (20%) | 21 (28%) | |
| MPA | 320 (54%) | 34 (45%) | |
| eGFR at diagnosis (ml/min) | |||
| Median (IQR) | 21 (12, 38) | 22 (14, 45) | 0.54 |
| Time from symptoms to renal biopsy (months) | |||
| Median (IQR) | 0.66 (0.00, 3.62) | 0.23 (0.00, 1.22) | 0.0028 |
| Organs | |||
| Lungb | 307 (52%) | 41 (55%) | 0.63 |
| Upper respiratoryb | 221 (37%) | 22 (29%) | 0.20 |
| Kidney | 597 (100%) | 75 (100%) | |
| Induction with plasmapheresis b | 78 (13%) | 20 (27%) | 0.0047 |
| Induction therapy | 0.48 | ||
| Prednisone alone | 54 (9%) | 8 (11%) | |
| Cyclophosphamide | 486 (81%) | 60 (80%) | |
| Othersc | 40 (7%) | 3 (4%) | |
| Not treated | 17 (3%) | 4 (5%) | |
| Follow-up (months), median (IQR) | 26 (10, 55) | 28 (5, 52) | 0.64 |
a
p-Values were calculated by Fisher exact test for categorical variables and Wilcoxon two samples for continuous variables.
b
There was 1 patient who had missing data for ANCA type and 1 patient who had missing data for lung involvement, 2 patients who had missing data for upper respiratory tract involvement and 2 patients who had missing data for induction therapy.
c
Azathioprine, mycophenolate mofetil, methotrexate, rituximab, and intravenous immunoglobulin.