Table 1.
Clinical characteristics of COVID-19 patients with and without ILD.
| ILD group (n = 26) | Non-ILD group (n = 52) | p-value | |
|---|---|---|---|
| Patient characteristics | |||
| Age (years), median (IQR) | 74.5 (67.3–82.5) | 74.5 (67.0–83.0) | 1.000 |
| Male, n (%) | 20 (76.9) | 40 (76.9) | 1.000 |
| BMI (kg/m2), median (IQR) | 22.7 (20.3–25.0) | 23.3 (21.4–26.1) | 0.450 |
| Smoker, n (%) | 19 (73.1) | 34 (65.3) | 0.082 |
| Comorbidities, n (%) | |||
| Diabetes mellitus | 8 (30.8) | 15 (28.8) | 1.000 |
| Cardiovascular disease | 6 (23.1) | 14 (26.9) | 0.789 |
| Hypertension | 12 (46.2) | 26 (50.0) | 0.813 |
| COPD | 9 (34.6) | 8 (15.4) | 0.080 |
| SpO2/FiO2 on admission, median (IQR) | 453 (351–457) | 452 (438–457) | 0.265 |
| SOFA score, median (IQR) | 1 (0–2) | 1 (0–1) | 0.369 |
| COVID-19 pneumonia, n (%) | 21 (80.8) | 47 (90.4) | 0.287 |
| ILD, n(%) | |||
| IPF | 6 (23.1) | - | - |
| Unclassifiable IIPs | 6 (23.1) | - | - |
| CTD-ILD | 6 (23.1) | - | - |
| ILA | 3 (11.5) | - | - |
| Other ILD | 5 (19.2) | - | - |
| Treatment before COVID-19, n(%) | |||
| Corticosteroids | 7 (26.9) | 1 (1.9) | 0.002 |
| Immunosuppressants | 4 (15.4) | 1 (1.9) | 0.040 |
| Antifibrotics | 3 (11.5) | 0 (0) | - |
| LTOT before admission | 4 (15.4) | 0 (0) | - |
| Lung function test | |||
| Subject number, n | 15 | 0 | |
| FVC (L), mean (SD) | 2.4 (2.0–3.4) | - | - |
| FVC (percentage of predicted), mean (SD) | 88.4 (65.3–105.9) | - | - |
| DLCO, (ml/min/kPa), mean (SD) | 12.1 (8.7–14.0) | - | - |
| DLCO, (percentage of predicted), mean (SD) | 66.5 (56.6–92.3) | - | - |
| Admission blood results, median (IQR) | |||
| WBC (/μL) | 6025 (4420–8315) | 5430 (4400–6820) | 0.316 |
| Lymphocyte (/μL) | 911 (618–1318) | 1071 (710–1278) | 0.398 |
| LDH (U/L) | 251 (204–347) | 249 (194–294) | 0.262 |
| CRP (mg/dL) | 4.5 (2.0–9.5) | 4.5 (2.0–10.3) | 0.621 |
| Ferritin (ng/mL) | 487 (245–646) | 466 (159–760) | 0.898 |
| KL-6 (U/mL) | 719 (462–1022) | 275 (228–362) | <0.001 |
| D-dimer (μg/mL) | 1.1 (0.80–2.79) | 1.07 (0.73–1.49) | 0.431 |
| Treatment, n (%) | |||
| Corticosteroid | 20 (76.9) | 40 (76.9) | 1.000 |
| Favipiravir | 16 (61.5) | 32 (61.5) | 1.000 |
| Remdesivir | 11 (42.3) | 17 (32.7) | 0.458 |
| Tocilizumab | 7 (26.9) | 4 (7.7) | 0.036 |
| Baricitinib | 3 (11.5) | 4 (7.7) | 0.680 |
| Oxygen therapy | 18 (69.2) | 28 (53.8) | 0.229 |
| NIPPV/HFNC | 8 (30.8) | 1 (1.9) | <0.001 |
| Intubation | 1 (3.8) | 5 (9.6) | 0.657 |
| ECMO | 0 (0) | 1 (1.9) | - |
| Outcome | |||
| Severe disease, n(%) | 11 (42.3) | 12 (23.1) | 0.114 |
| Death, n(%) | 3 (11.5) | 2 (3.8) | 0.326 |
| Time to recovery, median (IQR) | 20 (11.5–34.5) | 12 (9.5–19.5) | 0.029 |
| LTOT started after discharge from hospital, n(%) | 6 (23.1) | 4 (7.7) | 0.065 |
Continuous variables are shown as medians (interquartile ranges).
Fisher's exact tests were performed on categorical variables.
Mann-Whitney U tests were used to compare the non-ILD group and ILD groups.
BMI: body mass index, COPD: chronic obstructive pulmonary disease, COVID-19: coronavirus disease 2019, CRP: C-reactive protein, CTD: connective-tissue disease, DLCO: diffusing capacity for carbon monoxide, ECMO: extracorporeal membrane oxygenation, FiO2: fraction of inspiratory oxygen, FVC: forced vital capacity, HFNC: high-flow nasal cannula, IIPs: idiopathic interstitial pneumonias, ILA: interstitial lung abnormalities, ILD: interstitial lung disease, IPF: idiopathic pulmonary fibrosis, IQR: interquartile range, KL-6: Krebs von den Lungen-6, LDH: lactate dehydrogenase, LTOT: long-term oxygen therapy, NIPPV: noninvasive positive pressure ventilation, SOFA: sequential organ failure assessment, SpO2: saturation of percutaneous oxygen, WBC: white blood cell.