Table 2.
Descriptive analysis of SSc patients characteristics by clusters
| Cluster 1 (C1) | Cluster 2 (C2) | Cluster 3 (C3) | p-value | ||
|---|---|---|---|---|---|
| Demography | |||||
| Age, years | n | 86 | 120 | 43 | |
| Median (Q1;Q3) | 64 (53;73) | 58 (43;66) | 62 (52;69) | <0.001 | |
| Sex | n | 86 | 120 | 43 | |
| Female | n (%) | 72 (83.7) | 109 (90.8) | 31 (72.1) | 0.014 |
| Race | n | 86 | 120 | 43 | 0.604 |
| Asian | n (%) | 0 (0) | 1 (0.8) | 1 (2.3) | |
| Black/African American | n (%) | 0 (0) | 0 (0) | 0 (0) | |
| Caucasian/White | n (%) | 85 (98.8) | 118 (98.3) | 42 (97.7) | |
| Native Hawaiian/Pac. Isl. | n (%) | 1 (1.2) | 0 (0) | 0 (0) | |
| Other | n (%) | 0 (0) | 1 (0.8) | 0 (0) | |
| Autoantibodies | |||||
| Cent B | n | 73 | 103 | 35 | |
| Positive | n (%) | 39 (53.4) | 58 (56.3) | 8 (22.9) | 0.002 |
| SCL70 | n | 72 | 101 | 35 | |
| Positive | n (%) | 21 (29.2) | 34 (33.7) | 24 (68.6) | <0.001 |
| SSA | n | 72 | 100 | 35 | |
| Positive | n (%) | 11 (15.3) | 17 (17) | 8 (22.9) | 0.572 |
| SSB | n | 73 | 103 | 35 | |
| Positive | n (%) | 1 (1.4) | 1 (1.0) | 2 (5.7) | 0.225 |
| U1 RNP | n | 72 | 101 | 35 | |
| Positive | n (%) | 6 (8.3) | 5 (5.0) | 6 (17.1) | 0.076 |
| Clinical features | |||||
| Pericarditis | n | 80 | 111 | 41 | 0.749 |
| No | n (%) | 77 (96.2) | 109 (98.2) | 39 (95.1) | |
| Past | n (%) | 2 (2.5) | 2 (1.8) | 1 (2.4) | |
| Present | n (%) | 1 (1.2) | 0 (0) | 1 (2.4) | |
| Systemic hypertension | n | 86 | 120 | 43 | |
| Yes | n (%) | 35 (40.7) | 30 (25.0) | 15 (34.9) | 0.054 |
| Pulmonary fibrosis | n | 78 | 110 | 43 | |
| Yes | n (%) | 29 (37.2) | 32 (29.1) | 25 (58.1) | 0.004 |
| Skin Fibrosis | n | 86 | 119 | 43 | 0.092 |
| No | n (%) | 21 (24.4) | 44 (37.0) | 9 (20.9) | |
| Past | n (%) | 1 (1.2) | 2 (1.7) | 2 (4.7) | |
| Present | n (%) | 64 (74.4) | 73 (61.3) | 32 (74.4) | |
| DLCO | n | 36 | 68 | 22 | |
| % predicted value | Median (Q1;Q3) | 61 (51;74) | 64 (51;76) | 59 (45;72) | 0.536 |
| FVC | n | 38 | 71 | 22 | |
| % predicted value | Median (Q1;Q3) | 94 (71;110) | 98 (86;109) | 89 (71;99) | 0.246 |
| SSc classificationa | n | 43 | 76 | 22 | 0.003 |
| dcSSc | n (%) | 17 (39.6) | 18 (23.7) | 14 (63.6) | |
| lcSSc | n (%) | 22 (51.2) | 37 (48.7) | 5 (22.7) | |
| ssSSc | n (%) | 4 (9.3) | 21 (27.6) | 3 (13.6) | |
| Treatment | n | 86 | 120 | 43 | |
| Hydroxychloroquine | n (%) | 4 (4.7) | 13 (10.8) | 4 (9.3) | 0.286 |
| Immunosuppressants | n (%) | 23 (26.7) | 19 (15.8) | 23 (53.5) | <0.001 |
| Biologicals | n (%) | 3 (3.5) | 2 (1.7) | 2 (4.7) | 0.473 |
| Steroids | n (%) | 19 (22.1) | 11 (9.2) | 29 (67.4) | <0.001 |
| Systemic antibiotics | n (%) | 0 (0) | 2 (1.7) | 3 (7.0) | nc |
DLCO diffusing capacity of the lungs for carbon monoxide, FVC forced vital capacity, HV healthy volunteers, Pac. Isl. Pacific islanders, dcSSc diffuse cutaneous SSc, lcSSc limited cutaneous SSc, ssSSc sine scleroderma SSc. Statistical analyses: chi-square test of independence for categorical variables and Kruskal–Wallis test for continuous variables (nc, not calculable).
aSSc classification was performed on 141 out of 249 patients. n, number of patients with available information.