Table 1.
Characteristics of patients with Idiopathic Pulmonary Fibrosis (IPF), Interstitial Pneumonia with Autoimmune Features (IPAF), and Connective Tissue Disease-associated Interstitial Lung Disease (CTD-ILD)
| IPF (N=499) |
IPAF (N=250) |
CTD-ILD* (N=248) |
p-value for Comparison across Diagnoses | |
|---|---|---|---|---|
| Age, mean (SD) | 65.7 (9.6) | 60.5 (11.1) | 53.8 (13.4) | <0.0001 |
| Male Gender, N (%) | 368 (74) | 112 (45) | 70 (28) | <0.0001 |
| Ethnicity, N (%) | ||||
| Non-Hispanic White | 437 (87) | 170 (68) | 138 (56) | |
| Hispanic or Latino | 34 (7) | 26 (10) | 30 (12) | |
| Black | 17 (4) | 36 (14) | 75 (30) | <0.0001 |
| Asian | 6 (1) | 12 (5) | 5 (2) | |
| Other or Unknown | 5 (1) | 6 (2) | 0 | |
| Ever Smoker, N (%) | 317 (66) | 134 (54) | 105 (42) | <0.0001 |
| Family History | 61 (20) | 10 (4) | 7 (3) | <0.0001 |
| Pulmonary Function Test | ||||
| FVC % predicted, mean (SD), N | 67 (18), 418 | 64 (19), 228 | 68 (19), 214 | 0.08 |
| DLCO % predicted, mean (SD), N | 47 (17), 386 | 48 (18), 212 | 53 (20), 197 | 0.001 |
| Telomere Length | N=499 | N=244 | N=248 | |
| Observed-Expected, mean (SD), N | −0.17 (0.32) | −0.05 (0.29) | −0.04 (0.25) | <0.0001† |
| <10th percentile, N (%) | 156 (31) | 40 (16) | 32 (13) | <0.0001† |
| Single Nucleotide Polymorphisms, MAF (95% CI), N‡ | ||||
| MUC5B rs35705950 | 34.2 (31.1–37.5), 437 | 23.2 (18.8–28.2), 166 | 19.9 (15.5–25.2), 138 | <0.0001§ |
| TOLLIP rs5743890 | 12.4 (10.3–14.8), 437 | 15.0 (11.4–19.5, 163 | 14.2 (10.4–19.1), 137 | 0.42 |
| Follow-up in years, median (IQR) | 2.97 (1.54–4.86) | 2.86 (1.25–3.71) | 4.60 (1.88–8.21) | <0.0001 |
| Disease Progressionǁ | ||||
| Δ FVC % predicted/year, % (95% CI), N | −5.37 (−6.10, −4.66), 212 | −1.80 (−2.70, −1.0), 163 | −0.64 (−0.99, −0.30), 181 | <0.0001 |
| Survival | ||||
| Median Transplant-Free Survival, years (95% CI) |
3.75 (3.48–4.40) | 5.61 (4.88–7.07) | 11.88 (9.18-NA) | <0.0001 |
CTD-ILD diagnoses include scleroderma (N=74), rheumatoid arthritis (N=62), mixed connective tissue disease (N=35), dermatomyositis (N=22), polymyositis (N=18), anti-synthetase syndrome (N=3), primary Sjogren’s syndrome (N=20), systemic lupus erythematosus (N=12), polymyalgia rheumatic (N=2), overlap syndrome (N=2)
Bonferroni-corrected p-values for pairwise comparison between diagnoses for telomere length: IPF vs IPAF p<0.0001, IPF vs CTD-ILD p<0.0001, IPAF vs CTD-ILD p=1.0
Restricted to non-Hispanic white patients
Bonferroni-corrected p-values for pairwise comparison between diagnoses for MUC5B MAF: IPF vs IPAF p=0.00088, IPF vs CTD-ILD p<0.0001, IPAF vs CTD-ILD p=1.0
Restricted to patients with ≥3 FVC measurements over span of ≥90 days
Abbreviations: FVC, forced vital capacity; DLCO, diffusion capacity of lung for carbon monoxide, MAF, minor allele frequency