Table 1.
Participant characteristics
| Variable | SSc (n = 407) | SSc-ILD (n = 252) | SSc No-ILD (n = 155) | P-value | |
|---|---|---|---|---|---|
| Age at biomarker collection | 58.81 (50.51–66.40) | 58.67 (50.56–66.69) | 59.24 (49.46–65.51) | 0.719 | |
| Disease duration, years | 8.29 (3.38–16.98) | 6.83 (2.52–15.63) | 7.65 (2.43–15.58) | 0.742 | |
| Follow-up period, years | 6.31 (3.11–9.22) | 6.50 (2.85–9.16) | 6.09 (3.56–9.45) | 0.699 | |
| Sex, n (%) | Male | 80 (19.7) | 50 (19.8) | 30 (19.4) | 0.905 |
| Female | 327 (80.3) | 202 (80.2) | 125 (80.6) | ||
| Caucasian, n (%) | No | 45 (11.1) | 37 (14.7) | 8 (5.2) | 0.003 |
| Yes | 361 (88.9) | 215 (85.3) | 146 (94.8) | ||
| Disease subtype, n (%) | Limited | 272 (66.8) | 152 (60.3) | 120 (77.4) | <0.001 |
| Diffuse | 135 (33.2) | 100 (39.7) | 35 (22.6) | ||
| Antibody profile, n (%) | ANA positive | 386 (94.8) | 242 (96.0) | 144 (92.9) | 0.166 |
| Centromere | 124 (30.7) | 49 (19.6) | 75 (48.7) | <0.001 | |
| Scl-70 | 105 (26.1) | 89 (35.6) | 16 (10.5) | <0.001 | |
| RNA Polymerase III | 49 (15.2) | 31 (15.3) | 18 (15.1) | 0.972 | |
| FVC% | 92.4 (22.60) | 87.5 (21.88) | 100.4 (21.5) | <0.001 | |
| PAH, n (%) | 70 (17.2) | 42 (16.7) | 28 (18.1) | 0.717 | |
| Died during follow-up, n (%) | 120 (29.5) | 85 (33.7) | 35 (22.6) | 0.017 | |
| FVC% drop >10% during follow-up, n (%) | 281 (72.6) | 178 (75.4) |
Bold typeface used for statistically significant results (P ≤ 0.05).
SSc-ILD: SSc-associated interstitial lung disease; FVC%: forced vital capacity percentage predicted; PAH: pulmonary arterial hypertension.