Page 102 - Recognizing axial spondyloarthritis - Janneke de Winter

CHAPTER SIX
Spondylitis Spine Score, MRI magnetic resonance imaging, BASDAI Bath ankylosing spondylitis disease activity index
Table 2. Demographic and disease characteristics of HLA-C*07 positive and negative axSpA patients of the SPACE cohort
Male (n, %)
Age (mean, SD)
HLA-B*27 positive (n, %) Positive family history (n, %) Duration of back pain in months (mean, SD) Inflammatory back pain (n, %) Peripheral arthritis (n, %) Enthesitis (n, %)
Dactylitis (n, %)
IBD (n, %)
Psoriasis (n, %)
Uveitis (n, %)
CRP, mg/mL (mean, SD)
ESR, mm/h (mean, SD)
MNY criteria (n, %) Sacroiliitis on MRI (n, %) BASDAI (mean, SD)
Positive (n=28)
9 (32.1) 30.3 (8.4) 22 (78.6) 15 (53.8) 13.5 (8.2)
20 (71.4) 4 (14.8) 5 (17.9) 2 (7.1)
2 (7.1)
8 (28.6)
4 (14.3) 8.9 (12.9) 12.0 (12.8) 5 (17.9) 12 (46.2) 4.9 (1.7)
Negative (n=66) p-value
33 (50.0) .11 30.5 (8.1) .92 59 (89.4) .17 34 (51.5) .86 15.0 (7.9) .40
49 (74.2) .78 7 (10.6) .57 6 (9.1) .23 3 (4.5) .61 3 (7.0) .37 5 (7.6) .01 11 (16.7) .77 11.6 (13.1) .37 21.0 (21.9) .02 18 (27.7) .31 31 (48.4) .84 4.1 (2.1) .10
HLA-C*07 in axSpA patients
AxSpA axial Spondyloarthritis, SPACE SPondyloarthritis Caught Early, HLA human leukocyte antigen, IBD inflammatory bowel disease, CRP C-reactive protein, MNY modified New York, MRI magnetic resonance imaging, BASDAI Bath ankylosing spondylitis disease activity index
DISCUSSION
The major finding of the current study is that HLA-C*07 prevalence is decreased in axSpA. Based on original observations at the gene expression level and an initial genetic evaluation in a small exploratory cohort, we confirmed a lower HLA-C*07 prevalence in two different settings, showing a difference in HLA-C*07 prevalence not only in a cohort of patients with established AS, GESPIC, but also in an early chronic back pain cohort, SPACE. This enabled us to a) duplicate our findings in two different cohorts in two different countries, b) show that low HLA-C*07 prevalence is not restricted to full-blown AS but also observed in nr-axSpA, and c) establish that this association is independent of HLA-B*27 status. Furthermore, preliminary analyses in both cohorts suggest that HLA-C*07 negative axSpA patients have a lower prevalence of psoriasis but increased serum inflammatory markers and a higher prevalence of radiographic damage.
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