Table 1.
Comparison of clinical characteristics between case group and control group.
| Factors | AE-ILD (64) | Non-AE-ILD (128) | P-value |
|---|---|---|---|
| Age (y) | 60.5 (48.0, 66.0) | 60.0 (48.3, 65.0) | 0.726 |
| Sex (male/female) | 25/39 | 50/78 | 1.000 |
| Course of disease (m) | 3.0 (1.0, 6.8) | 4.0 (2.0, 8.8) | 0.122 |
| Duration of diagnosis delay (m) | 2.0 (1.0, 4.5) | 3.0 (1.0, 6.0) | 0.113 |
| Clinical manifestations or complications | |||
| Fever | 27 (42.2%) | 40 (31.3%) | 0.134 |
| Lymphadenectasis | 26 (40.6%) | 47 (36.7%) | 0.599 |
| Hepatomegaly | 1 (1.6%) | 1 (0.8%) | 1.000 |
| Splenomegaly | 14 (21.9%) | 21 (16.4%) | 0.355 |
| Heliotrope rash | 33 (51.6%) | 63 (49.2%) | 0.759 |
| Gottron's sign | 36 (56.3%) | 65 (50.8%) | 0.474 |
| Periungual erythema | 13 (20.3%) | 21 (16.4%) | 0.504 |
| Mechanic's hands | 9 (14.1%) | 17 (13.3%) | 0.881 |
| Raynaud's phenomenon | 4 (9.5%) | 8 (9.5%) | 1.000 |
| Muscle pain | 22 (34.4%) | 53 (41.4%) | 0.347 |
| Muscle weakness | 50 (78.1%) | 111 (86.7%) | 0.127 |
| Joint pain | 17 (26.6%) | 24 (18.8%) | 0.213 |
| Joint swelling | 8 (12.5%) | 21 (16.4%) | 0.476 |
| Dysphagia | 11 (17.2%) | 27 (21.1%) | 0.522 |
| Dysarthria | 5 (7.8%) | 8 (6.3%) | 0.919 |
| Respiratory muscle involvement | 2 (3.1%) | 7 (5.5%) | 0.717 |
| Cardiac involvement | 4 (6.3%) | 10 (7.8%) | 0.922 |
| Gastrointestinal hemorrhage | 9 (14.1%) | 15 (11.7%) | 0.643 |
| Bacterial infection | 14 (21.9%) | 21 (16.4%) | 0.355 |
| Fungal infection | 15 (23.4%) | 22 (17.2%) | 0.301 |
| Tuberculosis infection | 3 (4.7%) | 3 (2.3%) | 0.402 |
| EBV or CMV infection | 2 (3.1%) | 6 (4.7%) | 0.890 |
| Carcinoma | 6 (9.4%) | 11 (8.6%) | 0.857 |
| UIP pattern | 15 (23.4%) | 23 (18.0%) | 0.370 |
| Pneumomediastinum | 4 (6.3%) | 6 (4.7%) | 0.909 |
| On-admission disease activity | |||
| MYOACT score | 10.0 (8.0,12.0) | 7.0 (5.0,9.0) | <0.001 |
| Pulmonary function test | |||
| FVC% (%) | 66.1 ± 17.9 | 67.4 ± 19.2 | 0.684 |
| TLC (L) | 3.1 (2.6,4.3) | 3.6 (2.9,4.2) | 0.107 |
| FEV1% (%) | 66.8 ± 15.8 | 70.4 ± 21.3 | 0.288 |
| FEV1/FVC | 0.8 (0.7,0.9) | 0.8 (0.8,0.9) | 0.335 |
| DLCO% (%) | 53.6 ± 15.4 | 62.3 ± 20.5 | 0.009 |
| On-admission laboratory findings | |||
| ALT (U/L) | 49.0 (22.8,122.3) | 50.0 (27.0,134.0) | 0.710 |
| AST (U/L) | 48.0 (29.5,105.8) | 61.5 (31.5,163.3) | 0.283 |
| Cr (μmol/L) | 52.0 (43.0,69.0) | 49.5 (43.0,59.0) | 0.129 |
| LDH (U/L) | 421.0 (330.8,619.3) | 401.0 (300.5,820.8) | 0.844 |
| CK (U/L) | 179.0 (54.3,958.5) | 484.5 (58.0,2465.5) | 0.113 |
| CK-MB (U/L) | 31.5 (18.3,55.5) | 32.0 (19.0,110.0) | 0.210 |
| CRP (mg/L) | 10.1 (4.5,43.7) | 6.1 (2.3,18.8) | 0.004 |
| Ferritin (ng/ml) | 821.7 (342.9,2034.5) | 532.7 (247.4,1205.9) | 0.027 |
| ANA | 40 (62.5%) | 75 (58.6%) | 0.603 |
| Comorbidities/Harmful hobbies | |||
| Smoking | 14 (21.9%) | 26 (20.3%) | 0.802 |
| Alcohol abuse | 10 (15.6%) | 24 (18.8%) | 0.593 |
| Hypertension | 22 (34.4%) | 28 (21.9%) | 0.063 |
| Diabetes | 8 (12.5%) | 12 (9.4%) | 0.504 |
| Hepatitis | 4 (6.3%) | 15 (11.7%) | 0.232 |
| Allergic History | 4 (6.3%) | 21 (16.4%) | 0.049 |
| Immunosuppressive therapy | |||
| Steroid monotherapy | 19 (29.7%) | 37 (28.9%) | 0.911 |
| Steroid + DMARDs | 29 (45.3%) | 71 (55.5%) | 0.184 |
| Steroid + IVIG | 13 (20.3%) | 12 (9.4%) | 0.034 |
| Steroid + DMARDs + IVIG | 3 (4.7%) | 8 (6.3%) | 0.913 |
| IIM subtypes | |||
| DM | 36 (56.3%) | 72 (56.3%) | 1.000 |
| PM | 15 (23.4%) | 44 (34.4%) | 0.122 |
| CADM | 13 (20.3%) | 12 (9.4%) | 0.034 |
AE-ILD, Acute exacerbation of interstitial lung disease; y, years; m, months; EBV, Epstein-Barr virus; CMV, Cytomegalo virus; UIP pattern, Usual interstitial pneumonia pattern; MYOACT, Myositis Disease Activity Assessment Visual Analog Scales; FVC%, Percent-predicted forced vital capacity; TLC, Total lung capacity; FEV1%, Percent-predicted forced expiratory volume in 1 s; FEV1/FVC, Ratio of FEV1 over FVC; DLCO%, Percent-predicted diffusing capacity of the lung for carbon monoxide; ALT, Glutamic pyruvic transaminase; AST, Glutamic oxaloacetic transaminase; Cr, Serum creatinine; LDH, Lactate dehydrogenase; CK, Creatine kinase; CK-MB, Creatine kinase isoenzymes; ANA, Antinuclear antibody; DMARDs, Disease-modifying anti-rheumatic drugs; IVIG, Intravenous immunoglobulin; IIM, Idiopathic inflammatory myopathies; DM, dermatomyositis; PM, Polymyositis; CADM, Clinically amyopathic dermatomyositis.