Table 2.
Comparison of clinical characteristics between IPAF, CTD-ILD and IPF
| IPAF (n = 54) |
CTD-ILD (n = 76) |
Seronegative IPF (n = 145) |
Seropositive IPF (n = 30) |
P-value | |
|---|---|---|---|---|---|
| Sex (male) (n, %) | 19 (35.2) | 24 (31.6) | 103 (71.0) | 22 (73.3) | < 0.001 |
| Mean age (SD) | 67.9 ± 10.5 | 61.6 ± 13.5 | 71.6 ± 9.5 | 71.8 ± 8.3 | < 0.001 |
| Ever smoker (n, %) | 15 (27.8) | 23 (30.3) | 95 (65.5) | 20 (66.7) | < 0.001 |
| Smoking pack years | 7.0 ± 14.9 | 11.1 ± 20.4 | 24.6 ± 23.1 | 26.7 ± 32.1 | < 0.001 |
| ILD pattern from HRCT | < 0.001 | ||||
| UIP | 14 (25.9) | 35 (46.1) | 145 (100) | 30 (100) | |
| NSIP | 34 (63.0) | 17 (22.4) | 0 (0) | 0 (0) | |
| OP | 3 (5.6) | 5 (6.6) | 0 (0) | 0 (0) | |
| NSIP + OP | 2 (3.7) | 3 (3.9) | 0 (0) | 0 (0) | |
| LIP | 0 (0) | 2 (2.6) | 0 (0) | 0 (0) | |
| Emphysema from HRCT (n, %) | 5 (9.3) | 17 (22.4) | 45 (31.0) | 9 (30) | 0.006 |
| Lung biopsy at diagnosisa | < 0.001 | ||||
| None | 20 (37.0) | 33 (43.4) | 86 (59.3) | 14 (46.7) | |
| TBLB | 13 (24.1) | 11 (14.5) | 38 (26.2) | 12 (40) | |
| VATS | 25 (46.3) | 21 (27.6) | 18 (12.4) | 9 (30) | |
| FVC, L | 2.4 ± 0.7 | 2.6 ± 0.8 | 2.5 ± 0.8 | 2.8 ± 0.9 | 0.063 |
| FVC (% of predicted) | 81.8 ± 17.0 | 86.2 ± 18.4 | 80.7 ± 19.1 | 83.8 ± 17.6 | 0.225 |
| FEV1, L | 1.9 ± 0.6 | 2.0 ± 0.6 | 2.0 ± 0.6 | 2.2 ± 0.7 | 0.127 |
| FEV1/FVC | 82.0 ± 7.7 | 79.1 ± 9.4 | 82.1 ± 8.9 | 79.9 ± 9.6 | 0.109 |
| TLC, L | 3.8 ± 1.2 | 4.1 ± 1.0 | 4.4 ± 1.4 | 4.5 ± 1.3 | 0.077 |
| TLC (% of predicted) | 87.8 ± 21.6 | 91.1 ± 18.7 | 91.6 ± 24.5 | 84.5 ± 19.0 | 0.434 |
| VC,L | 2.4 ± 0.7 | 2.6 ± 0.8 | 2.7 ± 0.8 | 2.8 ± 0.9 | 0.116 |
| VC (% of predicted) | 84.5 ± 17.7 | 87.4 ± 19.5 | 80.6 ± 19.2 | 82.0 ± 18.3 | 0.224 |
| DLCO (absolute) | 10.6 ± 4.4 | 10.6 ± 3.6 | 11.4 ± 6.0 | 9.7 ± 4.4 | 0.361 |
| DLCO (% of predicted) | 62.7 ± 21.0 | 62.3 ± 18.2 | 68.5 ± 24.3 | 57.9 ± 19.0 | 0.059 |
Abbreviations: CTD-ILD connective tissue disease-related interstitial lung disease, DLCO Diffusing capacity of the lungs for carbon monoxide, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, HRCT high-resolution computed tomography scan, ILD interstitial lung disease, IPAF interstitial pneumonia with autoimmune features, IPF idiopathic pulmonary fibrosis, LIP lymphocytic interstitial pneumonia, NSIP nonspecific interstitial pneumonia, OP organizing pneumonia, SD standard deviation, TBLB transbronchial lung biopsy, TLC total lung capacity, UIP usual interstitial pneumonia, VATS video-assisted thoracoscopic surgery, VC vital capacity
aSome patients underwent multiple diagnostic procedures