Table 1.
Summary of the clinical characteristics and laboratory data
| PM | DM | CADM | |||
|---|---|---|---|---|---|
| ILD (N = 11) | No ILD (N = 12) | ILD (N = 11) | No ILD (N = 13) | ILD (N = 15) | |
| Sex (male/female) | 2/9 | 5/7 | 2/9 | 4/9 | 5/10 |
| Age (%) | 66.0 (58.0–72.5) | 68.5 (62.3–71.3) | 65.0 (53.5–68.0) | 68.0 (51.0–78.0) | 63.0 (60.5–69.0) |
| Smoking history (%) | 1 (9 %) | 6 (50 %) | 3 (27 %) | 2 (15 %) | 6 (40 %) |
| Days from onset | |||||
| To 1st visit | 44.0 (14.0–109) | 184 (59.0–761) | 68.0 (29.5–96.5) | 97.0 (63.0–238) | 17.0 (9.50–38.5) |
| To treatment | 62.0 (24.0–151) | 235 (133–902) | 80.0 (50.3–175) | 127 (108–282) | 31.0 (15.5–100) |
| Department for the first visit (%) | |||||
| Respiratory medicine | 8 (73 %) | 0 | 4 (36 %) | 0 | 9 (60 %) |
| Rheumatology | 3 (27 %) | 4 (33 %) | 6 (55 %) | 8 (62 %) | 4 (27 %) |
| Neurology | 0 | 8 (67 %) | 1 (9 %) | 3 (23 %) | 0 |
| Dermatology | 0 | 0 | 0 | 2 (15 %) | 2 (13 %) |
| Symptom and signs (%) | |||||
| Skin | |||||
| Gottron’s sign / papule | 0 | 0 | 6 (55 %) | 10 (77 %) | 9 (60 %) |
| Heliotrope eruption | 0 | 0 | 3 (27 %) | 10 (77 %) | 8 (53 %) |
| V / Shawl neck sign | 0 | 1 (8 %) | 4 (36 %) | 6 (46 %) | 4 (27 %) |
| Mechanic’s hands | 0 | 0 | 2 (18 %) | 1 (8 %) | 2 (13 %) |
| Muscle | |||||
| Myalgia | 3 (27 %) | 5 (42 %) | 8 (73 %) | 2 (15 %) | 4 (27 %) |
| Muscle weakness | 10 (91 %) | 12 (100 %) | 6 (55 %) | 13 (100 %) | 0 |
| Lung | |||||
| Dry cough | 5 (45 %) | 0 | 3 (27 %) | 0 | 9 (60 %) |
| Dyspnea on exertion | 2 (18 %) | 1 (8 %) | 2 (18 %) | 0 | 9 (60 %) |
| Others | |||||
| Fever | 8 (73 %) | 1 (8 %) | 7 (64 %) | 1 (8 %) | 12 (80 %) |
| Laboratory data | |||||
| C-reactive protein (mg/dl) | 1.06 (0.535–3.28) | 0.125 (0.0800–0.320) | 0.730 (0.330–1.96) | 0.320 (0.110–0.610) | 1.27 (0.495–2.92) |
| Krebs von den Lungen-6 (U/ml) | 870 (568–1340) | 273 (127–288) | 648 (297–1020) | 241 (234–289) | 905 (596–1197) |
| Surfactant protein D (ng/dl) | 119 (68.8–180) | 52.3 (45.2–62.0) | 70.1 (45.5–182) | 23.1 (17.2–73.3) | 64.7 (29.8–117) |
| Aspartate aminotransferase (IU/l) | 85.0 (62.0–150) | 51.5 (35.5–100) | 66.0 (48.0–157) | 68.0 (54.0–158) | 40.0 (28.5–56.5) |
| Alanine aminotransferase (IU/l) | 50.0 (31.5–111) | 27.0 (16.5–75.0) | 50.0 (29.0–79.5) | 43.0 (28.0–101) | 20.0 (17.0–32.5) |
| Lactate dehydrogenase (IU/l) | 571 (429–772) | 317 (263–670) | 496 (357–645) | 513 (441–759) | 342 (283–381 |
| Creatine phosphokinase (IU/l) | 1547 (599–2657) | 1212 (402–3347) | 874 (270–3000) | 965 (617–4872) | 232 (108–316) |
| Aldolase (U/l) | 28.5 (11.1–45.2) | 18.1 (5.15–22.8) | 15.5 (7.75–31.9) | 11.4 (8.40–30.9) | 7.40 (3.45–8.95) |
| Antinuclear antibody (%) | 8 (73 %) | 7 (58 %) | 7 (64 %) | 9 (69 %) | 8 (53 %) |
| Anti-Jo-1 antibody (%) | 1 (9 %) | 0 | 1 (9 %) | 1 (8 %) | 0 |
| Anti-MDA5 antibody | NA | NA | NA | NA | 8/13 |
| Lung function test | |||||
| %Forced vital capacity | 76.5 (59.8–93.8) | NA | 76.5 (53.0–81.7) | NA | 83.1 (70.4–91.3) |
| %Diffusing capacity for carbon monoxide | 65.7 (56.0–73.6) | NA | 61.3 (47.1–64.0) | NA | 58.2 (54.6–62.4) |
Categorical data are presented as numbers (percentages). Continuous data are presented as the median (interquartile range). Abbreviations: NA, not applicable