| Immunology | Results | Frequency |
| Anti-nuclear antibodies (n = 9) | Positive | 8 |
| Negative | 1 | |
| Anti Scl 70 antibodies( n = 7) | Positive | 3 |
| Negative | 4 | |
| Native anti DNA antibodies( n = 7) | Positive | 1 |
| Negative | 6 |