Table 1.
Demographics and clinical parameters of the MCTD and SSc cohorts
| SSc | MCTD | |
|---|---|---|
| Patients, N | 298 | 162 |
| Females, N (%) | 243 (82) | 128 (79) |
| Diffuse cutaneous SSc, N (%) | 78 (26) | N/A |
| Age at diagnosis, years, M (SD) | 48.3 (15.4) | 35.4 (15.7) |
| Age at blood sampling, M (SD) | 56.0 (13.8) | 44.7 (14.9) |
| Disease duration at sampling, years, Mdn (IQR) | 4.0 (9) | 7.0 (7) |
| Deceased, N (%) | 58 (20) | 14 (9) |
| Observation time, months, M (SD) | 55.0 (28.7) | 98.8 (27.4) |
| Classification criteria: | ||
| ACR/EULAR 2013 SSc, N (%) | 298 (100) | N/A |
| Alarcon, N (%) | N/A | 143 (88) |
| Sharp, N (%) | N/A | 151 (93) |
| Kasukawa, N (%) | N/A | 142 (88) |
| Pulmonary fibrosis at sampling, N (%) | 103/252 (40) | 52/148 (35) |
| % of predicted FVC, N (%) | 297 (100) | 146 (90) |
| % of predicted FVC, M (SD) | 94,7 (20,5) | 92.1 (18.5) |
| % of predicted DLCO, N (%) | 295 (99) | 142 (88) |
| % of predicted DLCO, M (SD) | 68.2 (21.7) | 73.8 (16.4) |
| Digital ulcers, N (%) | 132/278 (44) | 50/155 (32) |
| Precapillary pulmonary hypertension, N (%) | 44 (15) | 3 (.05) |
| Pulmonary arterial hypertension, N (%) | 32 (10.7) | 2 (.04) |
| Scleroderma renal crisis, N (%) | 12 (4) | 0 (0) |
MCTD mixed connective tissue disease, SSc systemic sclerosis, N numbers, N/A not applicable, M mean, SD standard deviation, Mdn median, IQR interquartile range, FVC forced vital capacity, DLCO diffusing capacity of the lungs for carbon monoxide