Table 1.
Baseline characteristics
| Characteristics | N = 213 (total) | N = 100 (tested for S. aureus colonization) |
|---|---|---|
| Female, n (%) | 116 (54.5%) | 60 (60%) |
| ENT limited AAV, n (%) | 36 (16.9%) | 20 (20%) |
| Ethnicity, n (%) | ||
| Caucasian | 145 (68.1%) | 75 (75%) |
| Asian | 1 (0.5%) | 1 (1%) |
| Other | 6 (2.8%) | 3 (3%) |
| Unknown | 61 (28.6%) | 21 (21%) |
| Age in years at onset of disease, median (IQR) | 53 (40–62) | 50 (35–60) |
| Age in years at last visit, median (IQR) | 63 (51–74) | 61 (48–73) |
| Deceased, n (%) | 32 (15.0%) | 14 (14%) |
| AAV type, n (%) | ||
| GPA | 178 (83.6%) | 83 (83%) |
| EGPA | 24 (11.3%) | 12 (12%) |
| MPA | 4 (1.9%) | 1 (1%) |
| Unspecified | 7 (3.3%) | 4 (4%) |
| ANCA at diagnosis, n (%) | ||
| PR3 | 127 (59.6%) | 65 (65%) |
| MPO | 32 (15.0%) | 14 (14%) |
| Negative | 34 (16.0%) | 14 (14%) |
| Unknown | 20 (9.4%) | 7 (7%) |
| Biopsy performed, n (%) | 173 (81.2%) | 86 (86%) |
| Biopsy supporting AAV diagnosis, n (%) | 101 (47.4%) | 49 (49%) |
| BVAS3 at diagnosis, median (IQR) | 13 (7–21) | 12 (6–21) |
| BVAS3 at last visit, median (IQR) | 0 (0–4) | 0 (0–4) |
| Induction therapy | ||
| Cyclophosphamide | 143 (67.1%) | 61 (61%) |
| Methylprednisolone pulse therapy | 58 (27.2%) | 29 (29%) |
| Methotrexate | 20 (9.4%) | 13 (13%) |
| Rituximab | 46 (21.6%) | 34 (34%) |
| Plasmapheresis | 17 (8.0%) | 4 (4%) |
| Mofetil mycophenolate | 7 (3.2%) | 0 (0%) |
| Azathioprine | 4 (1.9%) | 0 (0%) |
| IVIG | 1 (0.5%) | 0 (0%) |
| Cyclosporine | 1 (0.5%) | 0 (0%) |
| CCX168 (avacopan) | 1 (0.5%) | 1 (1%) |
| Omalizumab | 1 (0.5%) | 0 (0%) |
| Mepolizumab | 1 (0.5%) | 1 (1%) |
| Maintenance therapy | ||
| Azathioprine | 153 (71.8%) | 75 (75%) |
| Mofetil mycophenolate | 33 (15.5%) | 20 (20%) |
| Rituximab | 33 (15.5%) | 17 (17%) |
| Methotrexate | 22 (10.3%) | 16 (16%) |
| Cyclophosphamide | 1 (0.5%) | 0 (0%) |
| Cyclosporine | 2 (0.9%) | 0 (0%) |
| Mepolizumab | 4 (1.9%) | 3 (3%) |
| Follow-up time in years, median (IQR) | 8 (3–17) | 8 (3–18) |
| Number of relapses per patient year, median (IQR) | 0.1 (0–0.2) | 0.1 (0–0.2) |
| History of one or more ENT relapses, n (%) | 78 (36.6%) | 40 (40%) |
| S. aureus colonization test performed | 100 (46.9%) | 100 (100%) |
| S. aureus colonization, n (%) | 44 (20.7%) | 44 (44%) |
| Subglottic stenosis at diagnosis, n (%) | 16 (7.5%) | 6 (6%) |
| Subglottic stenosis at last visit, n (%) | 17 (8.0%) | 8 (8%) |
| Saddle nose at diagnosis, n (%) | 11 (5.2%) | 7 (7%) |
| Use of nasal steroids, n (%)a | 80 (37.6%) | 51 (51%) |
| Antibiotic treatment with positive S. aureus, n (%)c | 28/44 (63.6%) | |
| Cotrimoxazole | 22/44 (50%) | |
| Azithromycin | 2/44 (4.5%) | |
| Mupirocin ointment | 17/44 (38.6%) | |
| Unknown | 4/44 (9.1%) | |
| Antibiotic treatment with negative S. aureus, n (%)d | 12/56 (21.4%) | |
| Cotrimoxazole | 10/56 (17.9%) | |
| Azithromycin | 0/56 (0%) | |
| Mupirocin ointment | 11/56 (19.6%) | |
Values are median (interquartile range IQR) or n (%), P value ≤ 0.05
BVAS3 Birmingham vasculitis activity score version 3, ANCA anti-neutrophilic cytoplasmic autoantibody, AAV ANCA-associated vasculitis, ENT ear nose and throat
aDefined as receiving at least one prescription of nasal steroids during follow-up
bDefined as receiving at least one prescription of antibiotic treatment during follow-up regardless of the outcome of a performed S. aureus colonization test
cDefined as receiving at least one prescription of antibiotic treatment during follow-up and the presence of at least one positive S. aureus colonization test during follow-up
dDefined as receiving at least one prescription of antibiotic treatment during follow-up and the absence of S. aureus colonization in a performed test during follow-up