Table 1.
Descriptive statistics of GPA and MPA (numbers or median with lower and upper quartiles) at time of blood sampling.
| GPA | MPA | p value | |
|---|---|---|---|
| Age in years | 66.8 (50.9, 76.5) | 75.7 (68.8, 82.4) | p = 0.00241 |
| Sex (numbers) | |||
| Female | 18 | 11 | p ≥ 0.9992 |
| Male | 20 | 11 | |
| Age at diagnosis in years | 57.5 (35.9;67.3) | 64.2 (73.2;76.2) | p ≤ 0.00011 |
| Follow-up time in months | 81.9 (28.2;157.4) | 16.7 (1.2;74.8) | p = 0.0021 |
| ANCA specificity (numbers) | |||
| PR3 | 30 | 5 | p ≤ 0.00012 |
| MPO | 7 | 17 | |
| Disease activity (numbers) | |||
| Active disease | 8 | 10 | p = 0.07812 |
| Remission | 30 | 12 | |
| Time since onset of the last flare in months | 34.4 (11.4;63.2) | 8.9 (0.9;34.3) | p = 0.0601 |
| Disease phenotype (numbers) | |||
| Localized disease | 7 | 6 | p = 0.5202 |
| Systemic disease | 31 | 16 | |
| Organ involvement (numbers) | |||
| Ear-nose-throat | 30 | 1 | p ≤ 0.00012 |
| Pulmonal | 23 | 9 | p = 0.182 |
| Renal | 28 | 21 | p = 0.042 |
| Central nervous system | 4 | 1 | p = 0.6432 |
| Peripheral nervous system | 4 | 5 | p = 0.2672 |
| Gastrointestinal | 2 | 1 | p ≥ 0.9992 |
| Cardiovascular | 1 | 3 | p = 0.1352 |
| BVAS (Birmingham Vasculitis Activity Score) (numbers) | p = 0.053 | ||
| 0 | 30 | 12 | |
| 1–5 | 3 | 1 | |
| 6–10 | 4 | 4 | |
| >10 | 1 | 5 | |
| Vasculitis Damage Index | 2 (1, 4) | 2 (0, 3) | p = 0.2911 |
| CRP (mg/L) | 3.4 (1.4, 6.1) | 2.4 (1.4, 9.5) | p = 0.9541 |
| Haemoglobin (g/L) | 129.0 (122.5, 138.0) | 124.0 (111.0, 133.5) | p = 0.2311 |
| Platelets (109/L) | 263.0 (204.3, 313.3) | 230.0 (183.5, 287.5) | p = 0.1591 |
| White blood count (109/L) | 6.6 (5.2, 8.6) | 7.3 (5.4, 8.4) | p = 0.8811 |
| Creatinine (micromoles/L) | 101.0 (72.5, 141.0) | 158.0 (106.0, 199.3) | p = 0.0021 |
| eGFR (mL/min/1.73 m2) | 64 (45, 86) | 33 (21, 48) | p = 0.00011 |
| Prednisolone (mg/day) | p = 0.0063 | ||
| 0 | 11 | 7 | |
| 2.5–5 | 16 | 5 | |
| >5–10 | 10 | 2 | |
| >10–20 | 1 | 4 | |
| >20 | 0 | 4 | |
| Azathioprine | 12 | 8 | p ≥ 0.9992 |
| Median dose (mg/day) | 125 (range: 50, 200) | 75 (range: 50, 100) | p = 0.1001 |
| Mycophenolate mofetil | 5 | 0 | p = 0.1482 |
| Median dose (mg/day) | 2000 (range: 250, 2500) | NA | |
| Methotrexate | 5 | 0 | p = 0.1482 |
| Median dose (mg/week) | 25 (range: 15, 25) | NA | |
| Cyclophosphamide po | 0 | 0 | p = 0.5282 |
| Cyclophosphamide iv (within 6 months) | 4 | 7 | p = 0.0292 |
| Median time since last infusion (days) | 83.5 (31.8, 103.0) | 18 (12.3, 135.8) | p = 0.5041 |
| Rituximab (ever) | 14 | 3 | p = 0.0772 |
| Median time since last infusion (days) | 367.0 (139.5, 902.5) | 316.0 (91.0, 973.0) | p = 0.9531 |
GPA = granulomatosis with polyangitis; MPA = microscopic polyangitis. 1Mann-Whitney test, 2Fisher's exact test, and 3chi-square test.