Study population
| Groups | No of subjects | Mean age±SD | PASI±SD |
| Healthy controls | 28 (17 F, 11 M) | 45.6±16.3 | NA |
| Patients with psoriasis | 66 (33 F, 33 M) | 50.7±13.1 | 5.4±6.5 |
| Arthritic | 26 (15 F, 11 M) | 55.7±11.8 | 6.2±6.7 |
| Non-arthritic | 40 (20 F, 20 M) | 47.7±13.1 | 5±6.7 |
| Biological drugs treatment | 30 (15 F, 15 M) | 49.9±13.8 | 5.2±6.5 |
| No biological drugs treatment | 36 (17 F, 19 M) | 51.9±13.1 | 5.6±5.7 |
F, female; M, male; NA , not applicable; PASI, Psoriasis Area Severity Index.