Table 1.
Baseline characteristics: demographic and clinical features
| Characteristics | AxSpA (n=61) | Nr-axSpA (n=16) | AS (n=45) | HC (n=20) |
|---|---|---|---|---|
| Sex: male, n (%) | 44 (72.1) | 6 (37.5) | 38 (84.4) | 15 (75) |
| Age (years), mean (±SD) | 37.8 (13.3) | 37.1 (11.0) | 37.5 (14.2) | 37.3 (10.8) |
| BMI (kg/m 2 ), mean (±SD) | 26.0 (4.0) | 24.2 (3.9) | 26.6 (3.9) | - |
| HLA-B27, n (%) | 57 (93.4) | 15 (93.8) | 42 (93.3) | - |
| Disease duration (years), median (IQR) | 4.0 (0.6–8.0) | 0.2 (0.0–3.0) | 5.0 (2.0–8.0) | - |
| BASDAI, median (IQR) | 5.2 (2.6–7.4) | 4.8 (1.4–6.6) | 5.5 (3.4–7.6) | - |
| CRP (mg/l), median (IQR) | 9.7 (3.7–16.2) | 4.0 (1.2–10.8) | 11.1 (5.4–20.0) | - |
| Peripheral arthritis, n (%) | 30 (49.2) | 12 (75.0) | 18 (40.0) | - |
| Hip involvement, n (%) | 16 (26.2) | 3 (18.8) | 13 (28.9) | - |
| Enthesitis/Tendynitis, n (%) | 19 (31.1) | 9 (56.3) | 10 (22.2) | - |
| Extraarticular manifestations: | ||||
| IBD, n (%) | 1 (1.6) | 1 (6.3) | 0 (0.0) | - |
| Daktylitis, n (%) | 2 (3.3) | 2 (12.5) | 0 (0.0) | - |
| Psoriasis, n (%) | 4 (6.6) | 0 (0.0) | 4 (8.9) | - |
| Uveitis, n (%) | 21 (34.4) | 6 (37.5) | 15 (33.3) | - |
| First symptoms: | ||||
| Back pain, n (%) | 36 (59.0) | 8 (50.0) | 28 (62.2) | - |
| Uveitis, n (%) | 5 (8.2) | 0 (0.0) | 5 (11.1) | - |
| Peripheral Arthritis, n (%) | 8 (13.1) | 4 (25.0) | 4 (8.9) | - |
| Other, n (%) | 12 (19.7) | 4 (25.0) | 8 (17.8) | - |
| Treatment: | ||||
| NSA, n (%) | 37 (60.7) | 10 (62.5) | 27 (60.0) | - |
| csDMARDs, n (%) | 10 (16.4) | 5 (31.3) | 5 (11.1) | - |
| bDMARDs, n (%) | 15 (24.6) | 1 (6.3) | 14 (31.1) | - |
| TNC (ng/ml), median (IQR) | 535.3 (457.7–677.2) | 511.1 (416.7–700.9) | 535.3 (434.5–677.2) | 432.1 (329.1–565.9) |
AS, ankylosing spondylitis, axSpA, axial spondyloarthritis, BASDAI, Bath Ankylosing Spondylitis Disease Activity Index, BMI, body mass index, bDMARDs, biological disease-modifying anti-rheumatic drugs, CRP, C-reactive protein, csDMARDs, conventional synthetic disease-modifying anti-rheumatic drugs, n, number, NSAIDs, non-steroidal anti-inflammatory drugs, IBD, inflammatory bowel disease, IQR, interquartile range, nr-axSpA, non-radiographic axial spondyloarthritis