Table 2 Autoimmune disease-specific features in dermatomyositis and myositis patients
From: Enhanced systemic oxidative stress response in patients with idiopathic inflammatory myopathies
All IIM patients n = 56 | DM n = 18 | Myositis n = 38 | p-value DM vs. myositis | |
|---|---|---|---|---|
Clinical characteristics | ||||
Duration of the disease, years | 2.0 (0.5–5.0) | 1.0 (0.5–5.0) | 3.0 (0.8–7.8) | 0.17 |
Organ involvement | ||||
Interstitial lung disease, n (%) | 31 (55.4%) | 5 (27.8%) | 26 (68.4%) | 0.004 |
High probability of PAH, n (%) | 8 (14.3%) | 1 (5.6%) | 7 (18.4%) | 0.41 |
Raynaud's phenomenon, n (%) | 12 (21.4%) | 3 (16.7%) | 9 (23.7%) | 0.73 |
Cardiac involvement, n (%) | 3 (5.4%) | 1 (5.6%) | 2 (5.3%) | 1.00 |
Dysphagia, n (%) | 7 (12.5%) | 3 (16.7%) | 4 (10.5%) | 0.67 |
Systemic symptoms, n (%) | 24 (42.9%) | 10 (55.6%) | 14 (36.8%) | 0.19 |
Muscle weakness of upper extremities, n (%) | 30 (53.6%) | 11 (61.1%) | 19 (50.0%) | 0.44 |
Muscle weakness of lower extremities, n (%) | 37 (66.1%) | 13 (72.2%) | 24 (63.2%) | 0.50 |
Anti-nuclear antibodies | ||||
Anti-nuclear antibodies (IIF), n (%) | 53 (94.6%) | 17 (94.4%) | 36 (94.7%) | 1.00 |
Anti-nuclear antibodies (IIF), titer | 1:1280 (1:640–1:5120) | 1:1280 (1:320–1:5120) | 1:2560 (1:640–1:5120) | 0.27 |
Myositis-specific antibodies | ||||
Anti-Jo1, n (%) | 13 (23.2%) | 1 (5.6%) | 12 (31.6%) | 0.042 |
Anti-PL-7, n (%) | 4 (7.1%) | 0 (0.0%) | 4 (10.5%) | 0.29 |
Anti-PL12, n (%) | 4 (7.1%) | 1 (5.6%) | 3 (7.9%) | 1.00 |
Anti-OJ, n (%) | 2 (3.6%) | 0 (0.0%) | 2 (5.3%) | 1.00 |
Anti-EJ, n (%) | 1 (1.8%) | 0 (0.0%) | 1 (2.6%) | 1.00 |
Anti-Mi2, n (%) | 6 (10.7%) | 3 (16.7%) | 3 (7.9%) | 0.39 |
Anti-TIF1 gamma, n (%) | 4 (7.1%) | 2 (11.1%) | 2 (5.3%) | 0.59 |
Anti-MDA5, n (%) | 4 (7.1%) | 2 (11.1%) | 2 (5.3%) | 0.59 |
Anti-NXP2, n (%) | 4 (7.1%) | 2 (11.1%) | 2 (5.3%) | 0.59 |
Anti-SRP, n (%) | 2 (3.6%) | 0 (0.0%) | 2 (5.3%) | 1.00 |
Anti-SAE1, n (%) | 2 (3.6%) | 1 (5.6%) | 1 (2.6%) | 0.54 |
Myositis-associated autoantibodies | ||||
Anti-Ro 52, n (%) | 22 (39.3%) | 3 (16.7%) | 19 (50.0%) | 0.017 |
Anti-PM/Scl, n (%) | 11 (19.6%) | 3 (16.7%) | 8 (21.1%) | 0.73 |
Anti-Ku, n (%) | 4 (7.1%) | 0 (0.0%) | 4 (10.5%) | 0.29 |
Anti-SSA/SSB, n (%) | 1 (1.8%) | 0 (0.0%) | 1 (2.6%) | 1.00 |
Anti-Mitochondrial antibodies (M2), n (%) | 1 (1.8%) | 1 (5.6%) | 0 (0.0%) | 0.32 |
Anti-ds-DNA, n (%) | 3 (5.4%) | 0 (0.0%) | 3 (7.9%) | 0.54 |
Anti-RNAP-III, n (%) | 1 (1.8%) | 0 (0.0%) | 1 (2.6%) | 1.00 |
Laboratory measurements | ||||
Creatine kinase, IU/L | 84.5 (51–502) | 76.5 (51–342) | 97.0 (51–552) | 0.50 |
Myoglobin, μg/L | 42.8 (21–167) | 28.0 (20–153) | 52.6 (24–167) | 0.50 |