Table 1.
Demographic and clinical characteristics of patients with rare autoimmune rheumatic diseases and healthy age-matched controls
| Characteristics | RAIRD, n (%) (n = 50) | Controls, n (%) (n = 32) |
|---|---|---|
| Age (years) | ||
| Median (range) | 53 (22–81) | 53 (22–79) |
| 18–49 | 20 (40.0) | 14 (43.8) |
| 50–64 | 19 (38.0) | 14 (43.8) |
| ≥65 | 11 (22.0) | 4 (12.5) |
| Gender, n (%) | ||
| Female | 35 (70.0) | 23 (71.9) |
| Male | 15 (30.0) | 9 (28.1) |
| Ethnicity, n (%) | ||
| White | 45 (90.0) | 25 (78.1) |
| Non-white | 5 (10.0) | 7 (21.9) |
| Diagnosis, n (%) | ||
| ANCA-associated vasculitis | 31 (62.0) | |
| SLE | 9 (18.0) | |
| Other systemic vasculitis | 4 (8.0) | |
| Myositis | 6 (12.0) | |
| Current immunosuppression, n (%) | ||
| Methotrexate | 4 (8.0) | |
| Mycophenolate | 4 (8.0) | |
| Belimumab | 2 (4.0) | |
| Previous rituximab | 40 (80.0) | |
| ≤6 months | 17 (34.0) | |
| ≤12 months | 22 (44.0) | |
| Current glucocorticoids, n (%) | ||
| ≥10 mg/day | 7 (14.0) | |
| <10 mg/day | 10 (20.0) | |
| No steroids | 33 (66.0) | |
| Hypogammaglobulinemia, n (%) | 5 (6.0) | |
| Recent immunoglobulin therapya, n (%) | 4 (8.0) | |
| Vaccine type, n (%) | ||
| Oxford-AstraZeneca | 25 (50.0) | 8 (23.5) |
| Pfizer-BioNTech | 25 (50.0) | 26 (76.5) |
a
Excluded from the analysis on antibody response to vaccination.