Table 1.
Clinical characteristics of 121 patients with systemic sclerosis (SSc) according to the presence or absence of anti-centromere-associated protein antibodies (ACA)
| Variable | All patients | ACA-positive (n = 75) | ACA-negative (n = 46) | P-value |
|---|---|---|---|---|
| Female, n (%) | 113 (93.4) | 71 (94.7) | 42 (91.3) | 0.470a |
| Age at diagnosis, years | 38.8 (14.3) | 39.3 (13.7) | 37.8 (15.5) | 0.530b |
| Disease duration, years | 17.1 (10.3) | 18.4 (10.6) | 14.7 (9.4) | 0.050b |
| Limited disease, n (%) | 94 (77.7) | 70 (93.3) | 24 (52.2) | <0.0001 a |
| mRss | 5.70 (7.00) | 3.90 (6.40) | 9.00 (7.10) | <0.0001 b |
| FVC, % of predicted | 105.60 (20.20) | 107.40 (19.10) | 84.30 (22.20) | 0.014b |
| DLCO, % of predicted | 73.10 (23.80) | 76.60 (25.00) | 64.10 (17.80) | 0.017b |
| sPAP, mm Hg | 28.10 (10.60) | 27.70 (11.60) | 28.80 (8.80) | 0.058b |
| ILD, n (%) | 24 (27.6) | 13 (18.0) | 36 (78.6) | <0.0001a |
| PAH, n (%) | 16 (13.2) | 8 (10.7) | 8 (17.4) | 0.289a |
| Disease severity scale | ||||
| Total score | 5.89 (3.46) | 5.17 (2.80) | 7.20 (4.12) | 0.009b |
| General | 0.50 (0.80) | 0.44 (0.70) | 0.60 (0.93) | 0.484b |
| Peripheral vascular | 1.52 (0.71) | 1.46 (0.68) | 1.61 (0.76) | 0.212b |
| Skin | 0.83 (0.65) | 0.66 (0.64) | 1.14 (0.56) | <0.0001b |
| Joint/tendon | 0.47 (1.00) | 0.26 (0.64) | 0.85 (1.35) | 0.012b |
| Muscle | 0.16 (0.50) | 0.10 (0.42) | 0.26 (0.62) | 0.090b |
| Gastrointestinal tract | 0.83 (0.70) | 0.77 (0.66) | 0.94 (0.72) | 0.200b |
| Lung | 1.34 (1.11) | 1.22 (1.18) | 1.54 (0.96) | 0.111b |
| Heart | 0.24 (0.50) | 0.24 (0.42) | 0.25 (0.63) | 0.514b |
| Kidney | 0.05 (0.41) | 0.0 (0.0) | 0.14 (0.68) | 0.058b |
| Disease activity index | 1.52 (1.68) | 1.26 (1.31) | 1.98 (2.14) | 0.128b |
Values are presented as mean (SD) unless otherwise indicated. aChi-squared test; bMann-Whitney U-test. mRss, modified Rodnan skin score; FVC, forced vital capacity; DLCO, diffusing lung capacity for carbon monoxide; sPAP, systolic pulmonary arterial pressure; PAH, pulmonary arterial hypertension (sPAP >35 mm Hg); ILD, interstitial lung disease.