Parameter | AxSpA | No-axSpA (n=223) | All (n=403) | |
AS (n=88) | Nr-axSpA (n=92) | |||
Age, years (mean±SD) | 36.1±10.2 | 32.8±9.3 | 42.7±11.3 | 39.0±11.4 |
Male sex, n (%) | 60 (68.2) | 54 (58.7) | 79 (35.4) | 193 (47.9) |
HLA-B27 positive, n (%) | 79 (89.8) | 70 (76.1) | 83 (37.2) | 232 (57.6) |
Back pain duration, years (mean±SD) | 9.0±7.8 | 5.3±6.9 | 12.5±10.9 | 10.1±9.9 |
Peripheral oligoarthritis, n (%) | 12 (13.6) | 20 (21.7) | 32 (14.3) | 64 (15.9) |
Enthesitis, n (%) | 21 (23.9) | 16 (17.4) | 33 (14.8) | 71 (17.6) |
Dactylitis, n (%) | 2 (2.3) | 5 (5.4) | 10 (4.5) | 17 (4.2) |
Uveitis, n (%) | 13 (14.8) | 18 (19.6) | 11 (4.9) | 42 (10.4) |
History of IBD, n (%) | 2 (2.3) | 4 (4.4) | 0 (0) | 6 (1.5) |
Psoriasis, n (%) | 2 (2.3) | 13 (14.1) | 16 (7.2) | 31 (7.7) |
SpA family history, n (%) | 17 (19.3) | 24 (26.1) | 45 (20.1) | 86 (21.3) |
CRP, mg/L (mean±SD) | 11.0±16.4 | 7.1±9.2 | 2.9±4.3 | 5.7±9.9 |
ESR, mm/hour (mean±SD) | 22.7±20.8 | 15.2±13.3 | 12.0±10.3 | 15.2±14.6 |
Radiographic sacroiliitis according to the mNY criteria, n/N (%) | 78/85 (91.8) | 0/85 | 0/208 | 85/378 (22.5) |
Active inflammatory changes in the SIJ on MRI, n/N (%) | 37/48 (77.1) | 51/70 (72.9) | 2/77 (2.6) | 90/195 (46.2) |
Chronic inflammatory changes in the SIJ on MRI, n/N (%) | 32/48 (66.7) | 38/70 (54.3) | 0/77 (0) | 70/195 (35.9) |
Active inflammatory changes in the spine on MRI, n/N (%) | 15/36 (41.7) | 13/35 (37.1) | 5/84 (6.0) | 33/155 (21.3) |
Chronic inflammatory changes in the spine on MRI, n/N (%) | 11/36 (30.6) | 3/35 (8.6) | 3/84 (3.6) | 17/15 (11.0) |
AS, ankylosing spondylitis; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HLA, human leucocyte antigen; IBD, inflammatory bowel disease; MRI, MRI resonance imaging; SIJ, sacroiliac joint; SpA, spondyloarthritis; mNY criteria, modified New York criteria; nr-axSpA, non-radiographic axial spondyloarthritis.