Characteristics | At time of inclusion | At follow-up | HCs |
---|---|---|---|
 | (n = 84) | (n = 43) | (n = 28) |
Age in years (mean) | 37 (35-39) | 41 (38-43) | 42.9 |
Gender, percentage female | 58 | 59 | 57 |
Diagnosis, percentage of patients | Â | Â | Â |
 Ankylosing spondylitis | 19 | 19 | - |
 Psoriatic arthritis | 11 | 12 | - |
 Enteropathic arthritis | 4 | 5 | - |
 Reactive arthritis | 15 | 17 | - |
 Undifferentiated SpA | 51 | 47 | - |
HLA-B27, percentage positive | 60 | 55 | - |
Disease duration in years (mean) a | 8.0 (7.0-9.0) | 12.6 (9.8-15) | - |
Treatment, percentage of patients | Â | Â | Â |
 No | 67 | - | - |
 MTX | 8 | - | - |
 Salazopyrin | 11 | - | - |
 Anti-TNFα | 7 | 12 | - |
Self-assessment scores | Â | Â | - |
 BASDAI, 0-100 (mean) | 32 (26-37) | 35 (28-42) | - |
 BASFI, 0-100 (mean) | 20 (16-25) | 22 (16-28) | - |
 Patient pain, 0-100 (mean) | 32 (26-38) | 33 (26-41) | - |
 Patient global, 0-100 (mean) | 32 (26-38) | 31 (23-38) | - |
 Level of morning stiffness, 0-100 (mean) | 36 (29-43) | 36 (27-44) | - |
 Duration of morning stiffness, 0-100 (mean) | 33 (26-41) | 29 (20-38) | - |
Clinical scores | Â | Â | Â |
 BASMI, 0-100 (median) | 0 (0-0) | 0 (0-10) | - |
 Physician global, 0-100 (mean) | 16 (13-20) | 20 (16-25) | - |
 Thoracic chest expansion in cm (mean) | 4.1 (3.9-4.4) | 4.9 (4.5-5.3) | - |
Test results | Â | Â | Â |
 CRP in mg/L (median) | 2.1 (1.3-3.9) | 1.0 (0.5-2.5) |  |
 SIJ MRI activity, 0-40 (mean) | 7.5 (5.9-9.0) | 4.3 (2.9-5.7) | - |
 Spine MRI activity, 0-81 (median) | 1 (0-4) | 1 (0-2) | - |
 SIJ MRI chronicity, 0-48 (mean) | 15 (12-18) | 17 (13-22) | - |
 Spine MRI chronicity, 0-207 (median) | 0 (0-4) | 0 (0-5) | - |