Table 1.
Clinical and laboratory features of SSc patients.
| Characteristic | Elevated IL-31 levels (n = 43) | Normal IL-31 levels (n = 31) |
|---|---|---|
| Sex, no. of women/men | 40/3 | 27/4 |
| Age at onset, median (quartiles) years | 44 (30–63) | 53 (38–67) |
| Disease duration, median (quartiles) years | 1 (0–4) | 1 (0–3) |
| Disease pattern, No. with dcSSc/lcSSc | 39/4*** | 16/15 |
| MRSS, median (quartiles) points | 14 (10–20)*** | 8 (3–12) |
| Cutaneous vascular symptoms | ||
| Raynaud’s phenomenon | 93 | 90 |
| Nail fold bleeding | 67 | 52 |
| Telangiectasia | 53 | 45 |
| Pitting scars | 51 | 45 |
| Digital ulcers | 37 | 32 |
| Organ involvement | ||
| Lungs | ||
| Pulmonary fibrosis | 84*** | 35 |
| %VC, median (quartiles) % | 81 (70–90)*** | 93 (78–104) |
| %DLco, median (quartiles) % | 74 (60–88)** | 88 (74–94) |
| Pulmonary hypertension | 5 | 6 |
| Esophagus | 86* | 65 |
| Kidneys | 5 | 0 |
| Laboratory features | ||
| IL-4, median (quartiles) pg/ml | 16.2 (13.4–19.8)** | 13.4 (11.0–14.7) |
| IL-6, median (quartiles) pg/ml | 6.13 (2.7–25.0)** | 2.50 (1.8–4.3) |
| IL-13, median (quartiles) pg/ml | 49.8 (42.2–65.3)* | 45.7 (31.2–53.8) |
Unless noted otherwise, values are in percentage. *p < 0.05, **p < 0.01, ***p < 0.001 vs. patient with SSc with normal serum IL-31 levels. Significance was determined by Fisher’s exact probability test for comparison of proportions and two-tailed Mann–Whitney U test for quantitative variables. Source data are provided as a Source Data file.