Table 1.
Characteristics of patients at the time of diagnosis
| Sex | 12 male (39%) | |
| 19 female (61%) | ||
| Age [median, (IQR)] | 8.1 years (5.6–10.5) | |
| Weight, kg [median (IQR)] | 25.1 (19.2–36.5) | |
| Symptom duration prior to treatment [median, (IQR)] | 2.9 months (1.5–8.6) | |
| Muscle enzymes | Median (IQR) in U/L | Normal range in U/L |
| AST (n = 26) | 57 (47–177) | 8–60 |
| ALT (n = 26) | 48 (27–120) | 7–55 |
| CK (n = 28) | 328.5 (144–1957) | 29–308 |
| Aldolase (n = 28) | 12.3 (8.7–24.2) | < 14.5 |
| LDH (n = 16) | 773 (510–953) | 145–293 |
| MRI | Diagnostic in 6 out of 7 patients | |
| EMG | 1 | |
| Muscle Biopsy | 7 | |
| Myositis antibodies | 12 out of 19 positive (63%) | |
| Anti P155/140 | 4 (33%) | |
| Anti Mi-2 | 3 (25%) | |
| Unidentified S35 band | 5 (41%) |