Table 1. Patient and healthy control characteristics.
| HC | GPA | GPA–no relapse during follow-up | GPA–relapsed during follow-up | |
|---|---|---|---|---|
| subjects, n (% male) | 32 (53) | 84 (43) | 68 (43) | 16 (44) |
| Age, mean (range) | 56.8 (44–74) | 58.6 (26–83) | 60.2 (26–84) | 55.0 (32–76) |
| PR3-ANCA titer, median (range) | 1:80 (0–1:640) | 1:40 (0->640) | 1:80 (0->640) | |
| Creatinine umol/L, median (range) | 87 (57–409) | 87 (57–409) | 93 (61–171) | |
| eGFR ml/min*1,73m2, median (range) | 68 (13–111) | 65.5 (13–111) | 71 (26–95) | |
| CRP mg/L, median (range) | 4 (0.3–72) | 4 (0.3–72) | 4 (0.4–20) | |
| Disease duration in years, median (range) | 9.5 (0.2–42) | 8.8 (0.2–42) | 14.9 (2–24) | |
| Number of total relapses, median (range) | 1 (0–10) | 1 (0–6) | 4 (1–10) | |
| BVAS, median (range) | 0 (0–10) | 0 (0–10) | 0 (0–2) | |
| Clinical manifestations, n (%) | ||||
| Renal | 51 (61) | 40 (59) | 11 (69) | |
| ENT | 61 (73) | 49 (72) | 12 (75) | |
| Joints | 44 (52) | 34 (50) | 10 (63) | |
| Pulmonary | 56 (67) | 41 (60) | 15 (94) | |
| Nervous system | 26 (31) | 22 (32) | 4 (25) | |
| Eyes | 30 (36) | 22 (32) | 8 (50) | |
| Cutaneous | 18 (21) | 14 (21) | 4 (25) | |
| Other | 8 (10) | 5 (7) | 3 (19) | |
| Disease form, n (%) | ||||
| Localised | 3 (4) | 3 (4) | 0 (0) | |
| Early systemic | 13 (16) | 11 (16) | 2 (13) | |
| Generalised | 55 (66) | 43 (63) | 12 (75) | |
| Severe | 13 (16) | 11 (16) | 2 (13) | |
| Treatment at time of sampling, n (%) | ||||
| Aza | 9 (11) | 5 (7) | 4 (25) | |
| Pred | 9 (11) | 8 (12) | 1 (6) | |
| Aza + pred | 16 (19) | 13 (19) | 3 (19) | |
| MMF + pred | 8 (10) | 4 (6) | 4 (25) | |
| MTX | 1 (1) | 1 (2) | 0 (0) | |
| No immunosuppressive therapy | 41 (49) | 37 (54) | 4 (25) | |
| Induction therapy, n (%) | ||||
| Cyc, pred | 57 (68) | 47 (69) | 10 (63) | |
| Cyc, pred, followed by RTX | 8 (10) | 4 (6) | 4 (25) | |
| Cyc, pred, plasmapheresis | 13 (15) | 11 (16) | 2 (13) | |
| Pred, MTX | 2 (2) | 2 (3) | 0 (0) | |
| Co-trimoxazole | 4 (5) | 4 (6) | 0 (0) |
ANCA, anti-neutrophil cytoplasmic antibody; Aza, azathioprine; BVAS, Birmingham Vasculitis Activity Score; CRP, C-reactive protein; Cyc, cyclophosphamide; eGFR, estimated glomerular filtration rate; GPA, granulomatosis with polyangiitis; HC, healthy control; MMF, mycophenolate mofetil; MTX, methotrexate; pred, prednisolone; RTX, rituximab