Characteristics at baseline of adult and juvenile patients with DM. Values are mean ± SD unless otherwise specified.
| Variable | Adult DM, n = 21 | Juvenile DM, n = 26 | p |
|---|---|---|---|
| Age at baseline, yrs | 50.2 ± 17.8 | 9.7 ± 4.4 | < 0.001 |
| Female, n (%) | 17 (81) | 16 (62) | 0.15 |
| Disease duration, days, median (IQR) | 61 (6, 303) | 17 (0, 818) | 0.86 |
| White, n (%) | 20 (95) | 20 (77) | 0.08 |
| Corticosteroid use, n/n available (%) | 14/20 (70) | 8/21 (38) | 0.04 |
| Immunosuppressive agent use, n/n available (%) | 10/21 (48) | 6/21 (29) | 0.20 |
| Myositis autoantibody, n positive/n tested (%) | |||
| Antinuclear antibodies | 10/20 (50) | 12/18 (67) | 0.30 |
| Anti-Jo1 antibodies | 1/21 (5) | 1/21 (5) | 1.0 |
| Anti-RNP antibodies | 1/19 (5) | 1/18 (6) | 0.97 |
| Anti-dsDNA antibodies | 1/15 (7) | 0/16 (0) | 0.29 |
| Anti-SSA antibodies | 4/20 (20) | 1/18 (6) | 0.19 |
| Anti-SSB antibodies | 1/20 (5) | 0/18 (0) | 0.34 |
| Global extramuscular disease activity, 0–100 | 31.1 ± 20.6 | 31.1 ± 20.5 | 0.95 |
| Muscle disease activity, 0–100 | 34.0 ± 27.2 | 28.6 ± 29.2 | 0.41 |
| Physician’s global disease activity, 0–100 | 37.5 ± 23.5 | 36.5 ± 36.9 | 0.76 |
DM: dermatomyositis; IQR: interquartile range.