Patient characteristics and clinical data
| Characteristic | |
| Subjects n | 59 |
| Males | 54 (91.5) |
| Age years | 71.7±8.2 |
| Smoking history | 49 (86.0) |
| FVC before AE % predicted | 71.0±21.9 |
| DLCO before AE % predicted | 37.0±17.3 |
| Treatment before AE | |
| LTOT | 23 (39.0) |
| Corticosteroids | 20 (33.9) |
| Immunosuppressive agents | 10 (16.9) |
| WBC µL−1 | 10 490±4150 |
| D-dimer µg·mL−1 | 5.1±6.3 |
| CRP mg·dL−1 | 6.5±6.4 |
| LDH IU·L−1 | 380±226 |
| KL-6 U·mL−1 | 1763±1278 |
| P/F<200 | 26 (47.3) |
| BAL performed | 11 (18.6) |
| Treatment of AE | |
| High-dose corticosteroids | 59 (100) |
| Antibiotics | 58 (98.3) |
| Immunosuppressive agents | 30 (50.8) |
| Noninvasive ventilation | 14 (23.7) |
| 180-day mortality % | 59.2 |
The data are presented as mean±sd or n (%), unless otherwise indicated. FVC: forced vital capacity; AE: acute exacerbation; DLCO: diffusing capacity of the lung for carbon monoxide; LTOT: long-term oxygen therapy; WBC: white blood cell; CRP: C-reactive protein; LDH: lactate dehydrogenase; KL-6: Krebs von den Lungen-6; P/F: the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen; BAL: bronchoalveolar lavage.