| Age (years) | 32.0±7.0 | 32.8±7.8 | 0.4 |
| Male | 191 (65.6) | 50 (58.1) | 0.2 |
| Symptoms duration (months) | 13.0±6.7 | 9.3±6.2 | <0.001 |
| Enthesitis | 57 (19.6) | 43 (50) | <0.001 |
| Psoriasis | 33 (11.3) | 28 (32.6) | <0.001 |
| Dactylitis | 16 (5.5) | 28 (32.6) | <0.001 |
| IBD | 9 (3.1) | 10 (11.6) | 0.001 |
| Uveitis | 23 (7.9) | 1 (1.2) | 0.02 |
| Diarrhea, cervicitis, urethritis | 11 (0.8) | 5 (5.8) | 0.4 |
| Family history | 101 (34.7) | 31 (36) | 0.8 |
| HLA-B27 | 219 (75.3) | 28 (32.6) | <0.001 |
| CRP (mg/L) | 10.8±15.2 | 13.7±31.2 | 0.3 |
| ESR (mmHg) | 13.6±13.5 | 14.1±13.4 | 0.8 |
| SJC | 0.3±1.3 | 1.4±2.4 | <0.001 |
| VAS (0-10) physician | 2.9±2.2 | 2.4±2.1 | 0.1 |
| VAS (0-10) patient | 4.2±2.7 | 3.1±2.5 | <0.01 |
| BASDAI | 3.8±2.3 | 3.5±2.3 | 0.2 |