Summary of demographic and clinical data of the study subjects
| Healthy controls | ILD subjects | p-value | |
| Subjects n | 26 | 50 | |
| Age years | 55 (48–62) | 60 (50–69) | 0.07 |
| Male sex | 11 (41) | 21 (42) | 0.97 |
| Race | |||
| Caucasian | 14 (54) | 37 (74) | |
| African American | 7 (27) | 13 (26) | 0.53 |
| Diagnosis | |||
| IPAF | 18 (36) | ||
| Rheumatoid arthritis | 5 (10) | ||
| MCTD | 3 (6) | ||
| Myositis-related | 13 (26) | ||
| Scleroderma | 11 (22) | ||
| Pulmonary function tests | |||
| FVC % predicted | 61.5 (51–78) | ||
| DLCO % predicted | 42.5 (26–55) | ||
| UIP pattern | 11 (22) | ||
| Supplemental oxygen use | |||
| Subjects n (%) | 15 (20) | ||
| Flow rate L·min−1 | 2–3 |
Data are presented as median (interquartile range) or n (%), unless otherwise stated. ILD: interstitial lung disease; IPAF: interstitial pneumonia with autoimmune features; MCTD: mixed connective tissue disease; FVC: forced vital capacity; DLCO: diffusion capacity for carbon monoxide; UIP: usual interstitial pneumonia.