Clinical characteristics of patients and control subjects studied
| Group | n | Sex (M/F) | Age2-150(years) | Duration of disease2-150(years) | Autoantibody positive patients (n) | Disease activity index2-151 (points) |
| Patients with RA | 24 | 4/20 | 62 (32–76) | 13.5 (1–35) | Rheumatoid factor 20 | TAI 3–15 |
| Patients with SLE | 13 | 0/13 | 47 (23–69) | 4 (1–15) | Anti-dsDNA (pos) 10 | SLAM 3–11 |
| Patients with SSc | 6 | 1/5 | 53.5 (42–69) | 6.5 (1–11) | Anti-Scl-70 (pos) 4 | SSS 7–15 |
| Control subjects | 16 | 3/13 | 43 (27–56) |