Table 1.
Characteristics of the patients with AxSpA included in the study
| Total | Based on the left sacroiliac joint damage | p value | Based on the right sacroiliac joint damage | p value | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 grade | 1 grade | 2 grade | 3 grade | 4 grade | 0 grade | 1 grade | 2 grade | 3 grade | 4 grade | ||||
| Number of cases (n) | 186 | 4 | 8 | 73 | 72 | 29 | NA | 4 | 10 | 74 | 72 | 26 | NA |
| Age (years) | 26.4 ± 8.7 | 25.3 ± 5.4 | 29.4 ± 10.7 | 24.9 ± 8.7 | 27. 6 ± 8.3 | 26.5 ± 9.2 | 0.138 | 25.3 ± 5.4 | 25.7 ± 9.4 | 25.0 ± 8.6 | 27.9 ± 8.5 | 26.7 ± 9.4 | 0.133 |
| Male/female (n) | 143/43 | 3/1 | 6/2 | 55/18 | 54/18 | 25/4 | 0.763 | 3/1 | 7/3 | 57/17 | 53/19 | 23/3 | 0.564 |
| AxSpA duration (years) | 4.3 ± 4.0 | 0.8 ± 0.3 | 4.4 ± 2.5 | 3.1 ± 3.1 | 4.8 ± 3.7 | 6.9 ± 5.6 | <0.001 | 0.8 ± 0.3 | 4.5 ± 2.9 | 2.8 ± 2.2 | 5.1 ± 4.3 | 7.0 ± 5.5 | <0.001 |
| HLA-B27 (+/-) (n) | 164/22 | 3/1 | 6/2 | 68/8 | 65/7 | 25/4 | 0.725 | 3/1 | 9/1 | 64/10 | 66/6 | 22/4 | 0.741 |
| ESR (mm/h) | 25.1 ± 22.1 | 9.5 ± 10.6 | 10.1 ± 8.9 | 20.2 ± 16.5 | 29.1 ± 24.8 | 33.7 ± 25.7 | 0.002 | 9.5 ± 10.6 | 23.8 ± 20.1 | 19.2 ± 17.2 | 28.3 ± 23.9 | 35.8 ± 26.3 | 0.007 |
| CRP (mg/l) | 14.3 ± 17.5 | 1.0 ± 0.5 | 3.1 ± 2.4 | 9.2 ± 13.1 | 16. 6 ± 17.2 | 26.0 ± 23.4 | <0.001 | 1.0 ± 0.5 | 9.4 ± 15.6 | 9.9 ± 14.3 | 15.1 ± 15.9 | 28.1 ± 23.8 | <0.001 |
| Total back pain# | 4.9 ± 2.8 | 1.3 ± 0.5 | 1.9 ± 1.4 | 4.5 ± 2.6 | 5.4 ± 2.6 | 6.3 ± 2.8 | <0.001 | 1.3 ± 0.5 | 3.6 ± 3.2 | 4.5 ± 2.6 | 5.2 ± 2.6 | 6.6 ± 2.8 | <0.001 |
| PGA of disease activity# | 5.6 ± 3.0 | 2.5 ± 1.9 | 2.5 ± 1.8 | 5.3 ± 2.8 | 5.9 ± 2.9 | 7.0 ± 2.9 | <0.001 | 2.5 ± 1.9 | 4.4 ± 3.7 | 5.1 ± 2.8 | 5.9 ± 2.7 | 7.3 ± 3.0 | 0.002 |
| Pain and swelling of peripheral arthritis# | 0.2 ± 0.5 | NA | 0.3 ± 0.4 | 0.2 ± 0.4 | 0.3 ± 0.5 | 0.4 ± 0.6 | 0.249 | NA | 0.2 ± 0.4 | 0.2 ± 0.4 | 0.3 ± 0.5 | 0.4 ± 0.6 | 0.227 |
| Duration of morning stiffness# | 5.4 ± 2.8 | 2.8 ± 1.0 | 2.0 ± 1.3 | 5.1 ± 2.7 | 5.8 ± 2.6 | 6.4 ± 2.9 | <0.001 | 2.8 ± 1.0 | 4.0 ± 3.6 | 4.9 ± 2.6 | 5.8 ± 2.5 | 6.7 ± 2.9 | 0.003 |
| ASDAS (scores) | 2.7 ± 1.1 | 1.0 ± 0.2 | 1.4 ± 0.4 | 2.4 ± 1.3 | 3.0 ± 1.3 | 3.5 ± 1.5 | <0.001 | 1.0 ± 0.2 | 2.1 ± 1.6 | 2.4 ± 1.3 | 2.9 ± 1.3 | 3.6 ± 1.6 | <0.001 |
| BASFI (scores) | 4.3 ± 1.1 | 1.9 ± 0.8 | 2.5 ± 0.9 | 4.0 ± 1.0 | 4.6 ± 0.7 | 4.9 ± 0.8 | <0.001 | 1.9 ± 0.8 | 3.1 ± 1.5 | 4.1 ± 1.0 | 4.5 ± 0.8 | 4.9 ± 0.8 | <0.001 |
| Use of NSAIDs (ever/never) (n) | 169/17 | 0/4 | 8/0 | 68/5 | 67/5 | 26/3 | <0.001 | 0/4 | 10/0 | 70/4 | 66/6 | 23/3 | <0.001 |
| Use of DMARDs (≥3/<3 months) (n) | 169/17 | 1/3 | 6/2 | 69/4 | 68/4 | 25/4 | 0.005 | 1/3 | 8/2 | 70/4 | 67/5 | 23/3 | 0.010 |
| Ever use of biologic DMARDs (n) | |||||||||||||
| > 12 months | 28 | 0 | 4 | 18 | 4 | 2 | <0.001 | 0 | 5 | 15 | 6 | 2 | <0.001 |
| ≤ 12 months | 42 | 1 | 3 | 21 | 15 | 2 | 1 | 3 | 24 | 12 | 2 | ||
| ≤ 6 months | 59 | 2 | 1 | 16 | 30 | 10 | 2 | 0 | 18 | 32 | 7 | ||
| Never | 57 | 1 | 0 | 18 | 23 | 15 | 1 | 2 | 17 | 22 | 15 | ||
| Serum uric acid (μmol/L) | 362.7 ± 107.9 | 284.0 ± 95.3 | 345.1 ± 77.0 | 361.9 ± 105.5 | 366.0 ± 117.7 | 372.2 ± 97.8 | 0.593 | 284.0 ± 95.3 | 325.6 ± 103.5 | 362.3 ± 101.9 | 372.4 ± 118.8 | 363.3 ± 94.6 | 0.499 |
| MSU crystallization (+/-) (n) | |||||||||||||
| Sacroiliac joint | 111/261$ | 0/4 | 0/8 | 14/59 | 29/43 | 14/15 | <0.001 | 0/4 | 1/9 | 13/61 | 28/44 | 12/44 | 0.002 |
| Hip joint | 75/111 | 1/3 | 4/4 | 33/40 | 28/44 | 9/20 | 0.632 | 1/3 | 6/4 | 32/42 | 29/43 | 7/19 | 0.369 |
| Pubic symphysis | 63/123 | 0/4 | 3/5 | 25/48 | 28/44 | 7/22 | 0.244 | 0/4 | 4/6 | 25/49 | 29/43 | 5/21 | 0.112 |
| Volume of MSU crystallization (cm3) | |||||||||||||
| Sacroiliac joint | 0.29 ± 0.99$ | NA | NA | 0.10 ± 0.30 | 0.31 ± 0.69 | 0.75 ± 1.72 | 0.001 | NA | 0.01 ± 0.01 | 0.10 ± 0.32 | 0.41 ± 1.19 | 0.83 ± 2.11 | 0.005 |
| Total volume at pelvis | 4.37 ± 8.46 | 0.02 ± 0.03 | 0.63 ± 0.99 | 4.36 ± 8.01 | 4.92 ± 10.03 | 4.62 ± 6.72 | 0.077 | 0.02 ± 0.03 | 2.15 ± 4.16 | 4.00 ± 7.73 | 5.51 ± 10.37 | 3.78 ± 5.91 | 0.118 |
Values are given as the numbers or the mean ± standard deviation (Mean±SD);
AxSpA axial spondyloarthritis, n numbers, +/- positive/negative, ESR erythrocyte sedimentation rate, CRP C-reactive protein, PGA patient’s global assessment, ASDAS Ankylosing Spondylitis Disease Activity Score, BASFI Bath Ankylosing Spondylitis Functional Index, NSAIDs non-steroidal anti-inflammatory drugs, DMARDs disease-modifying anti-rheumatic drugs, MSU monosodium urate, NA not available
#All assessed on a visual analogue scale (0–10 cm)
$The sum of the data from the left and right sacroiliac joint