Table 2.
Demographic variables, pulmonary function tests, and densitometry considering scleroderma patients with less or greater pulmonary involvement.
| SSc-ILD (78) | SSc No-ILD (16) | p-value | ||
|---|---|---|---|---|
| SSc extensive- ILD (36) | SSc limited-ILD (42) | |||
| Demographic data | ||||
| Females | 34 (94%) | 38 (90%) | 15 (94%) | |
| Age (years) | 51.7 ± 14.6 | 58.9 ± 12.3 | 49.5 ± 11.0 | |
| BMI (kg/m2) | 25.8 ± 5.9 | 25.0 ± 5.7 | 25.4 ± 4.4 | |
| SSc cutaneous involvement | ||||
| lc-SSc | 22 (23%) | 30 (32%) | 12 (13%) | |
| dc-SSc | 14 (15%) | 12 (13%) | 4 (4%) | |
| Type of antibody | ||||
| Anti-topoisomerase I antibody | 4 (4%) | 5 (5%) | 4 (4%) | |
| Anti-centromere antibody | 23 (24%) | 25 (27%) | 2 (2%) | |
| Anti-RNA polymerase III | – | 2 (2%) | 1 (1%) | |
| Autoantibody not identified | 9 (9%) | 10 (11%) | 9 (9%) | |
| Pulmonary function tests | ||||
| FVC (% predicted) | 74.6 ± 22.0a, b | 112.1 ± 18.5 | 113.5 ± 17.0 | <0.001a, b |
| 50% < FVC < 70% | 18 (50%) | 0 (0%) | 0 (0%) | |
| FVC < 50% | 3 (8%) | 0 (0%) | 0 (0%) | |
| DLCO/VA (% predicted) | 84.1 ± 20.2 | 76.2 ± 18.5 | 88.3 ± 11.4 | |
| DLCO (% predicted) | 57.9 ± 17.9a, b | 73.7 ± 19.8c | 87.0 ± 13.3 | <0.001a, b 0.04c |
| DLCO <55% | 17 (47%) | 10 (24%) | 0 (0%) | |
| 55% < DLCO <80% | 14 (39%) | 12 (29%) | 5 (31%) | |
| FVC(%)/DLCO(%) | 1.35 ± 0.38 | 1.62 ± 0.49 | 1.33 ± 0.25 | 0.02a |
| FVC(%)/DLCO(%) > 1.4 and DLCO(%) <55% | 8 (22%) 1.86 ± 0.28a | 9 (21%) 2.35 ± 0.48 | 0 (0%) | 0.022 |
| CT densitometry | ||||
| TLV (mL) | 2,915.7 ± 673.9a, b | 4,286.3 ± 1,136.5 | 4,541.0 ± 800.4 | <0.001a, b |
| Total lung weight (g) | 723.3 ± 142.1 | 736.1 ± 158.7 | 780.7 ± 180.9 | |
| Hyperinflated (%) | 4.6 ± 3.1a, b | 9.8 ± 4.3 | 10.2 ± 4.5 | <0.001a, b |
| Normally aerated (%) | 58.7 ± 8.4a, b | 63.9 ± 4.5 | 67.8 ± 4.9 | 0.002a <0.001b |
| ILD Extent (%) | 36.7 ± 8.7a, b | 26.3 ± 2.1c | 22.0 ± 0.8 | <0.001a, b 0.03c |
Values are presented as mean ± standard deviation. Bold characters indicate statistically significant differences.
Statistically significant difference between SSc Extensive-ILD and SSc Limited-ILD.
Statistically significant difference between SSc Extensive-ILD and SSc No-ILD.
Statistically significant difference between SSc Limited-ILD and SSc No-ILD.
SSc No-ILD, scleroderma with no interstitial lung disease (ILD ≤ 25%); SSc-ILD, scleroderma with interstitial lung disease; SSc Limited-ILD, scleroderma with interstitial lung disease between 25 and 35%; SSc Extensive-ILD, scleroderma with interstitial lung disease higher than 35%; BMI, body mass index; FVC (%), forced vital capacity expressed as predicted values; DLCO/VA, carbon monoxide diffusion capacity adjusted for alveolar volume expressed as predicted values; DLCO (%), carbon monoxide diffusion capacity expressed as predicted values; TLV, total lung volume; Total lung weight, lung tissue fraction related to densities from −1,000 to +50 Hounsfield units (HU); Hyperinflated, tissue fraction related to densities from −1,000 to −901 HU; Normally Aerated, tissue fraction related to densities from −900 to −501 HU; ILD Extent, extent of interstitial lung disease defined as lung weight related to interstitial opacities normalized by total lung weight.