Table 3.
Characteristics of interstitial lung disease (ILD) in rheumatoid arthritis (RA) and non-RA patients
| RA patients with ILD (N=46) | Control subjects with ILD (N=7) | |
|---|---|---|
| Probable ILD, N (%) | 23 (50.0%) | 5 (71.4%) |
| Definite ILD, N (%) | 23 (50.0%) | 2 (28.6%) |
| Mean ± SD age at ILD diagnosis in years | 71.3±12.2 | 86.5±10.0 |
| Men, N (%) | 27 (58.7%) | 4 (57.1%) |
| Current smoker, N (%) | 15 (32.6%) | 1 (14.3%) |
| Former smoker, N (%) | 15 (32.6%) | 4 (57.1%) |
| Chest radiograph performed ever, N (%) | 45 (97.8%) | 7 (100%) |
| Chest CT performed ever, N (%) | 23 (50.0%) | 4 (57.1%) |
| Lung biopsy/autopsy performed ever, N (%) | 14 (30.4%) | 0 (0.0%) |
| ILD subtype† based on biopsy and/or CT, N (%) | ||
| UIP typical pattern | 9 (19.6%) | 3 (42.9%) |
| NSIP typical pattern | 1 (2.2%) | 0 (0.0%) |
| OP typical pattern | 3 (6.5%) | 0 (0.0%) |
| Pulmonary fibrosis, not further specified | 15 (32.6%) | 0 (0.0% |
| No CT or biopsy documented | 15 (32.6%) | 3 (42.9%) |
| PFT: TLC < 80%, N (%) | 15 (32.6%) | 2 (28.6%) |
| No TLC documented, N (%) | 21 (45.7%) | 4 (57.1%) |
*
Except where indicated otherwise, values are the number (%) of patients.
†
According to the American Thoracic Society consensus classification of idiopathic interstitial pneumonias [15].
RA = rheumatoid arthritis; ILD =interstitial lung disease; SD = standard deviation; UIP = usual interstitial pneumonia; NSIP = non- specific interstitial pneumonia; OP=organizing pneumonia; CT=computed tomogram; PFT = pulmonary function testing; TLC = total lung capacity