Background
Methods
Results
Clinical characteristics of the patients with AxSpA
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 |
Reproducibility of DECT MSU crystal volume measurement and correlation between the average MSU crystal volume and serum uric acid
Joint | Reader | Volume of MSU crystallization (cm3) | Intraclass correlation coefficient | Correlation with serum uric acid#
| ||||
---|---|---|---|---|---|---|---|---|
Mean ± SD | 95% CI |
ICC
| 95% CI |
p
|
r
|
p
| ||
Left sacroiliac joint (n = 57) | Reader 1 | 0.900 ± 1.351 | 0.541–1.258 | 0.999 | 0.998-0.999 | <0.001 | NA | NA |
Reader 2 | 0.904 ± 1.340 | 0.549–1.260 | NA | NA | ||||
Average | 0.902 ± 1.345 | 0.545–1.259 | NA | NA | NA | 0.727 | <0.001 | |
Right sacroiliac joint (n = 54) | Reader 1 | 1.078 ± 1.878 | 0.578–1.619 | 1.000 | 0.999-1.000 | <0.001 | NA | NA |
Reader 2 | 1.071 ± 1.878 | 0.5700–1.612 | NA | NA | ||||
Average | 1.074 ± 1.878 | 0.574–1.616 | NA | NA | NA | 0.740 | <0.001 | |
Pelvis (n = 154) | Reader 1 | 5.237 ± 8.942 | 3.813–6.660 | 0.999 | 0.999-0.999 | <0.001 | NA | NA |
Reader 2 | 5.307 ± 9.150 | 3.850–6.764 | NA | NA | ||||
Average | 5.272 ± 9.044 | 3.832–6.712 | NA | NA | NA | 0.896 | <0.001 |
Comparison of MSU crystal deposition and serum uric acid in patients grouped by ASDAS scores
ASDAS scores |
x
2
/Z/F
|
p
| ||||
---|---|---|---|---|---|---|
ASDAS < 1.3 (n = 38) | 1.3 ≤ ASDAS < 2.1 (n = 38) | 2.1 ≤ ASDAS ≤ 3.5 (n = 50) | ASDAS > 3.5 (n = 60) | |||
MSU crystallization (+/-) (n)#
| ||||||
Left sacroiliac joint | 8/30 | 6/32 | 16/34 | 27/33 | 11.451 | 0.010 |
Right sacroiliac joint | 3/35 | 4/34 | 11/39 | 36/24 | 43.684 | <0.001 |
Hip joint | 15/23 | 16/22 | 22/28 | 22/38 | 0.676 | 0.879 |
Pubic symphysis | 11/27 | 13/25 | 18/32 | 21/39 | 0.549 | 0.908 |
Volume of MSU crystallization (cm3)$
| ||||||
Left sacroiliac joint | 0.21 ± 0.62 | 0.14 ± 0.47 | 0.49 ± 1.34 | 0.23 ± 0.57 | 9.198 | 0.027 |
Right sacroiliac joint | 0.04 ± 0.18 | 0.13 ± 0.52 | 0.35 ± 1.09 | 0.57 ± 1.62 | 34.607 | <0.001 |
Total volume at pelvis | 2.41 ± 6.51 | 2.69 ± 5.04 | 7.40 ± 11.49 | 4.13 ± 7.77 | 10.517 | 0.015 |
Serum uric acid (μmol/L)& | 321.0 ± 100.4 | 326.2 ± 104.2 | 397.9 ± 109.4 | 382.9 ± 99.8 | 6.322 | <0.001 |
Unadjusted associations of clinical features with the grade of sacroiliac joint damage
Characteristics | Based on the left sacroiliac joint damage | Based on the right sacroiliac joint damage | ||||
---|---|---|---|---|---|---|
Unadjusted OR
|
95% CI
|
p value | Unadjusted OR
|
95% CI
|
p value | |
Age, per year | 1.016 | 0.985–1.047 | 0.324 | 1.025 | 0.994–1.057 | 0.121 |
Male, vs female | 1.303 | 0.692–2.454 | 0.412 | 1.281 | 0.680–-2.412 | 0.444 |
AxSpA duration, per year | 1.189 | 1.103–1.283 | <0.001 | 1.195 | 1.108–1.289 | <0.001 |
HLA-B27 positive, vs negative | 1.248 | 0.546–2.850 | 0.599 | 1.197 | 0.524–2.732 | 0.670 |
ESR, per mm/h | 1.024 | 1.011–1.037 | <0.001 | 1.023 | 1.010–1.036 | <0.001 |
CRP, per mg/l | 1.045 | 1.027–1.063 | <0.001 | 1.041 | 1.024–1.059 | <0.001 |
Total back pain, per score | 1.298 | 1.169–1.440 | <0.001 | 1.263 | 1.139–1.399 | <0.001 |
PGA of disease activity, per score | 1.214 | 1.104–1.335 | <0.001 | 1.221 | 1.110–1.343 | <0.001 |
Pain and swelling of peripheral arthritis, per score | 1.849 | 1.051–3.254 | 0.033 | 1.950 | 1.105–3.441 | 0.021 |
Duration of morning stiffness, per score | 1.242 | 1.122–1.376 | <0.001 | 1.234 | 1.115–1.367 | <0.001 |
ASDAS, per score | 1.716 | 1.397–2.107 | <0.001 | 1.671 | 1.362–2.048 | <0.001 |
BASFI, per score | 3.188 | 2.330–4.364 | <0.001 | 2.811 | 2.081–3.797 | <0.001 |
Ever use of NSAIDs, vs never | 1.893 | 0.740–4.842 | 0.183 | 1.372 | 0.543–3.471 | 0.504 |
Use of DMARDs ≥3 months, vs <3 months | 1.922 | 0.751–4.922 | 0.173 | 1.967 | 0.769–5.034 | 0.158 |
Ever use of biologic DMARDs, vs never | ||||||
≥ 12 months | 0.143 | 0.057–0.357 | <0.001 | 0.182 | 0.074–0.444 | <0.001 |
≤ 12 months | 0.274 | 0.127–0.592 | 0.001 | 0.244 | 0.113–0.531 | <0.001 |
≤ 6 months | 0.795 | 0.404–1.567 | 0.508 | 0.757 | 0.383–1.493 | 0.421 |
Never | NA | NA | NA | NA | NA | NA |
Serum uric acid, per μmol/L | 1.001 | 0.999–1.004 | 0.358 | 1.001 | 0.999–1.004 | 0.276 |
MSU crystallization positive, vs negative | ||||||
Left sacroiliac joint | 3.368 | 1.841–6.160 | <0.001 | NA | NA | NA |
Right sacroiliac joint | NA | NA | NA | 3.225 | 1.749–5.946 | <0.001 |
Hip joint | 0.715 | 0.415–1.232 | 0.227 | 0.674 | 0.390–1.163 | 0.156 |
Pubic symphysis | 0.971 | 0.554–1.703 | 0.919 | 0.928 | 0.529–1.628 | 0.795 |
Volume of MSU crystallization, per cm3
| ||||||
Left sacroiliac joint | 1.990 | 1.308–3.028 | 0.001 | NA | NA | NA |
Right sacroiliac joint | NA | NA | NA | 1.470 | 1.125–1.922 | 0.005 |
Total volume at pelvis | 1.015 | 0.983–1.047 | 0.370 | 1.015 | 0.983–1.047 | 0.367 |
Adjusted associations of clinical features with the grade of sacroiliac joint damage
Characteristics | Based on the left sacroiliac joint damage | Based on the right sacroiliac joint damage | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Complex model 1 | Simplified model 2 | Complex model 3 | Simplified model 4 | |||||||||
AOR
|
95% CI
|
p value |
AOR
|
95% CI
|
p value |
AOR
|
95% CI
|
p value |
AOR
|
95% CI
|
p value | |
AxSpA duration, per year | 1.187 | 1.089–1.294 | 0.000 | 1.180 | 1.086–1.283 | 0.000 | 1.188 | 1.090–1.295 | 0.000 | 1.190 | 1.096–1.293 | 0.000 |
ESR, per mm/h | 1.003 | 0.981–1.025 | 0.794 | 1.003 | 0.982–1.025 | 0.755 | 1.001 | 0.981–1.022 | 0.905 | 1.003 | 0.982–1.024 | 0.781 |
CRP, per mg/l | 1.038 | 0.999–1.079 | 0.058 | 1.018 | 0.991–1.046 | 0.194 | 1.025 | 0.987–1.065 | 0.196 | 1.008 | 0.981–1.036 | 0.576 |
Total back pain, per score | 1.428 | 1.040–1.962 | 0.028 | 1.246 | 0.975–1.591 | 0.078 | 1.315 | 0.959–1.803 | 0.089 | 1.166 | 0.916–1.484 | 0.212 |
PGA of disease activity, per score | 1.040 | 0.784–1.380 | 0.786 | 0.975 | 0.746–1.275 | 0.856 | 1.023 | 0.780–1.342 | 0.868 | 0.970 | 0.751–1.252 | 0.815 |
Pain and swelling of peripheral arthritis, per score | 1.517 | 0.795–2.897 | 0.207 | 1.356 | 0.725–2.534 | 0.341 | 1.858 | 0.978–3.532 | 0.059 | 1.657 | 0.890–3.084 | 0.111 |
Duration of morning stiffness, per score | 0.723 | 0.519–1.008 | 0.056 | 0.682 | 0.494–0.942 | 0.020 | 0.836 | 0.607–1.150 | 0.271 | 0.792 | 0.581–1.079 | 0.139 |
ASDAS, per score | 0.492 | 0.179–1.354 | 0.170 | NA | NA | NA | 0.526 | 0.194–1.429 | 0.208 | NA | NA | NA |
BASFI, per score | 3.837 | 2.263–6.506 | 0.000 | 3.800 | 2.250–6.417 | 0.000 | 3.092 | 1.896–5.044 | 0.000 | 3.034 | 1.870–4.922 | 0.000 |
Ever use of biologic DMARDs, vs never | ||||||||||||
≥ 12 months | 1.051 | 0.308–3.581 | 0.937 | 1.144 | 0.337–3.885 | 0.829 | 1.425 | 0.417–4.872 | 0.572 | 1.414 | 0.421–4.754 | 0.575 |
≤ 12 months | 0.961 | 0.333–2.778 | 0.942 | 1.098 | 0.385–3.132 | 0.861 | 0.971 | 0.329–2.866 | 0.958 | 1.020 | 0.357–2.916 | 0.971 |
≤ 6 months | 1.999 | 0.806–4.962 | 0.135 | 1.830 | 0.745–4.495 | 0.188 | 2.461 | 0.976–6.204 | 0.056 | 2.128 | 0.869–5.211 | 0.099 |
Never | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
MSU crystallization positive, vs negative | ||||||||||||
Left sacroiliac joint | 0.895 | 0.391–2.049 | 0.794 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
Right sacroiliac joint | NA | NA | NA | NA | NA | NA | 1.291 | 0.542–3.075 | 0.565 | NA | NA | NA |
Volume of MSU crystallization, per cm3
| ||||||||||||
Left sacroiliac joint | 2.018 | 1.144–3.560 | 0.015 | 1.920 | 1.209–3.049 | 0.006 | NA | NA | NA | NA | NA | NA |
Right sacroiliac joint | NA | NA | NA | NA | NA | NA | 1.387 | 1.022–1.882 | 0.036 | 1.418 | 1.075–1.870 | 0.014 |