Table 1.
Demographic and disease characteristics of the MDA5(+) patients
| PLEX | Serum | |
|---|---|---|
| n = 8 | n = 22a | |
| Demographics | ||
| Age at diagnosis (years), mean (s.d.) | 51.1 (10.7) | 43.7 (12.9) |
| Gender: male, n (%) | 5 (62.5) | 14 (63.6) |
| Ethnicity | ||
| Caucasian | 7 (87.5) | 21 (95.5) |
| African | 0 (0) | 0 (0) |
| Asian | 1 (12.5) | 1 (4.6) |
| Diagnosis | ||
| PM, n (%) | 0 (0) | 3 (13.6) |
| DM, n (%) | 5 (62.5) | 19 (86.4) |
| ADM, n (%) | 0 (0) | 1 (5.3) |
| CADM, n (%) | 3 (37.5) | 1 (5.3) |
| Myositis-associated autoantibodies | ||
| Anti-SSA/Ro52 positive, n (%) | 2 (25) | 11 (50.0) |
| Clinical symptoms at diagnosis | ||
| Muscular manifestations | ||
| Muscle weakness, n (%) | 3 (50)c | 8 (47.1)e |
| MMT8, mean (s.d.) | NA | 75.07 (6.7)g |
| Elevated muscle enzymes, n (%) | NA | 11 (68.8)f |
| Joint manifestations | ||
| Arthritis/arthralgia, n (%) | 3 (50)c | 9 (50.0)d |
| Dermatological manifestations | ||
| Heliotrope rash, n (%) | 4 (50) | 10 (55.6)d |
| Gottron’s papules/sign, n (%) | 7 (87.5) | 15 (83.3)d |
| Respiratory manifestations | ||
| TLC <80%, n (%) | NA | 12 (70.6)e |
| FVC <80%, n (%) | NA | 12 (70.6)e |
| DLCO <75%, n (%) | NA | 9 (69.2)h |
| ILD, n (%) | 8 (100) | 16 (88.9)d |
| RP-ILD, n (%) | 6 (75) | 3 (16.7)d |
| Disease course | ||
| Disease duration (months), median (IQR) | 2.0 (0.7–3.3) | 2.0 (1.0–3.0) |
| Immunosuppressive treatment, n (%) | 6 (100)c | 16 (72.7) |
| Time to plasmapheresis <2 months, n (%) | 6 (75) | NA |
| Time to plasmapheresis >2 months, n (%) | 2 (25) | NA |
| Deceased, n (%) | 4 (57.1)b | 2 (11.1) |
| Respiratory failure, n (%) | 4 (100) | 2 (100) |
| Radiographic lesions, n (%) | NA | 16 (88.9)d |
a
One patient was included in both collections. Missing data: b1, c2, d4, e5, f6, g8, h9. MDA5: melanoma differentiation–associated protein 5; PLEX: plasma exchange; ADM: amyopathic DM; CADM: clinically amyopathic DM; MMT8: Manual Muscle Test-8; TLC: total lung capacity; FVC: forced vital capacity; DLCO: diffusing capacity for carbon monoxide; ILD: interstitial lung disease; RP-ILD: rapidly progressing ILD; IQR: interquartile range; NA: not available/applicable.