Table 1. Clinical findings at the diagnosis of connective tissue disease-related interstitial lung disease.
| Radiologic PPFE-like lesion | ||||
|---|---|---|---|---|
| Total (n = 113) | Absent (n = 92) | Present (n = 21) | p | |
| Age (years) | 62 (56, 70) | 62 (55, 68) | 63 (63, 74) | 0.03 |
| Male | 47 | 40 | 7 | 0.47 |
| Body mass index (kg/m2) | 22.2 (20.2, 24.4) (n = 109) | 22.4 (20.5, 24.8) (n = 88) | 19.8 (17.3, 22.4) | <0.01 |
| Current or former smoker | 57 | 48 | 9 | 0.48 |
| Smoking pack-year | 0 (0, 38) (n = 111) | 5 (0, 38) | 0 (0, 40) (n = 19) | 0.47 |
| Occupational dust exposure | 16 (n = 94) | 11 (n = 76) | 5 (n = 18) | 0.18 |
| Dyspnea | 48 (n = 84) | 39 (n = 66) | 9 (n = 18) | 0.59 |
| Fine crackles on chest auscultation | 93 (n = 106) | 76 (n = 87) | 17 (n = 19) | 1.00 |
| Clubbed finger | 11 (n = 85) | 8 (n = 70) | 3 (n = 15) | 0.40 |
| PaO2 on room air (Torr) | 77 (69, 88) (n = 99) | 80 (69, 88) (n = 81) | 74 (69, 91) (n = 18) | 0.47 |
| PaCO2 (Torr) | 40 (38, 42) (n = 99) | 39 (38, 42) (n = 81) | 41 (39, 44) (n = 18) | 0.16 |
| LDH (IU/L) | 246 (211, 317) (n = 109) | 250 (214, 325) (n = 88) | 239 (189, 302) | 0.23 |
| KL-6 (U/mL) | 791 (520, 1185) (n = 109) | 800 (534, 1123) (n = 88) | 674 (491, 1361) | 0.84 |
| SP-D (ng/mL) | 177 (106, 271) (n = 104) | 173 (102, 262) (n = 83) | 207 (118, 294) | 0.46 |
| % predicted FVC (%) | 76 (64, 87) (n = 104) | 77 (65, 89) (n = 84) | 67 (60, 86) (n = 20) | 0.15 |
| % predicted DLCO (%) | 71 (58, 94) (n = 48) | 73 (60, 92) (n = 36) | 67 (42, 97) (n = 12) | 0.49 |
| Ratio of RV to TLC (%) (reference range: 22%–40%) | 39 (35, 44) (n = 47) | 38 (33, 41) (n = 35) | 44 (37, 47) (n = 12) | 0.02 |
| BALF-lymphocyte (%) | 6 (4, 13) (n = 82) | 6 (4, 14) (n = 67) | 6 (4, 10) (n = 15) | 0.59 |
Data are presented as n or median with interquartile range. All p values are evaluated by comparing between the patients with and without radiologic PPFE-like lesion, using Chi-square test, Fisher’s exact test, or Mann–Whitney’s U test as appropriate.
Definition of abbreviations: BALF = bronchoalveolar lavage fluid; DLCO = diffusing capacity of the lung for carbon monoxide; FVC = forced vital capacity; KL-6 = Krebs von den Lungen-6; LDH = lactate dehydrogenase; PPFE = pleuroparenchymal fibroelastosis; RV = residual volume; SP-D = surfactant protein-D; TLC = total lung capacity.