Characteristics of patients with anti-MDA5+DM
| Variable | Total (N=329) |
| General characteristics | |
| Age at initial visit, mean±SD, years | 48.6±11.5 |
| Female, n (%) | 219 (66.6) |
| Smoking history, n (%) | 53 (16.1) |
| Malignancy, n (%) | 12 (3.6) |
| Disease duration, median (IQR), months | 3.5 (2.0, 7.0) |
| ILD, n (%) | 308 (93.6) |
| RPILD, n (%) | 177 (53.8) |
| Pulmonary infection, n (%) | 216 (65.7) |
| Clinical features at initial visit | |
| Heliotrope rash, n (%) | 245 (74.5) |
| Gottron’s sign, n (%) | 270 (82.1) |
| Mechanic’s hand, n (%) | 182 (55.3) |
| Distal digital tip ulceration, n (%) | 91 (27.7) |
| V sign, n (%) | 165 (50.2) |
| Shawl sign, n (%) | 127 (38.6) |
| Myalgia, n (%) | 141 (42.9) |
| Muscle weakness, n (%) | 197 (59.9) |
| Fever, n (%) | 166 (50.5) |
| Laboratory findings | |
| Creatine kinase, median (IQR), IU/L | 51.0 (25.0, 116.0) |
| Lymphocyte count, median (IQR), ×109/L | 0.73 (0.50, 1.04) |
| Lactate dehydrogenase, median (IQR), IU/L | 308.0 (254.8, 399.3) |
| Ferritin*, median (IQR), ng/mL | 590.5 (256.2, 1169.9) |
| Anti-Ro-52 antibody-positive, n (%) | 206 (62.6) |
*Data were available for 314 patients.
Anti-MDA5+DM, anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis; ILD, interstitial lung disease; RPILD, rapidly progressive ILD.