Page 29 - Recognizing axial spondyloarthritis - Janneke de Winter

PERIPHERAL DISEASE IN AXIAL SPA
Tender joint count, median (IQR) 0-68 joints Schober, median (IQR) cm
Chest expansion, median (IQR) cm
CRP, median (IQR) mg/l
ESR, median (IQR) mm/h
NSAIDs, % Corticosteroids, % Any csDMARD, % Anti-TNF therapy, %
Purely axial SpA (n=112)
0.0 (0.0-0.0)
3.0 (2.0-4.0) 5.0 (4.0-6.0) 3.3 (1.0-8.5) 8.0 (5.0-15.3)
85 (76) 1 (1)
5 (5) 16 (14)
Combined SpA
(n=118)
1.0 (0.0-3.5)
4.0 (3.0-5.0)
4.0 (3.0-6.0)
4.0 (1.1-14.2)
12.0 (4.5- 24.5)
87 (74) 3 (3) 27 (23) 20 (17)
P-value <0.001
0.001 0.120 0.288 0.078
0.706 0.339 <.001 0.578
SpA spondyloarthritis; ASAS Assessment of SpondyloArthritis international Society; IQR interquartile range; IBD inflammatory bowel disease; BASDAI Bath Ankylosing Spondylitis Disease Activity Index; ASDAS Ankylosing Spondylitis Disease Activity Score; CRP C-reactive protein; ESR erythrocyte sedimentation rate; NSAIDs non-steroidal anti- inflammatory drugs; csDMARDs conventional synthetic disease-modifying anti-rheumatic drugs; TNF tumor necrosis factor. Significance of the comparisons is determined by Mann- Whitney U tests for continuous variables or chi-square tests for categorical variables. Data were missing for: diagnostic delay n=153, HLA-B27 n=25, BASDAI n=10, CRP n=57, SJC/TJC n=2, Schober n=11 and ESR n=47 individuals
DISCUSSION
In this real-life observational cohort of 314 SpA patients we investigated the clinical characteristics and disease burden of axial and peripheral SpA according to the ASAS criteria, leading to the following conclusions: 1) Patients classified as axial SpA according to the ASAS criteria in fact consist of two separate groups of equal size: patients with exclusively axial disease and patients with combined axial and peripheral disease, defined as active IBP plus arthritis, enthesitis and/ or dactylitis, 2) patients with combined axial and peripheral disease consistently showed higher disease activity than patients with purely axial disease, and 3) patients with combined axial and peripheral disease were less often treated with csDMARDs than patients with purely peripheral SpA.
In line with previous reports, axial SpA was more prevalent than peripheral SpA and was associated with specific features such as younger age, higher prevalence of HLA-B27 and uveitis, and lower prevalence of psoriasis and IBD (22). And in line with treatment guidelines (23), a majority of axial SpA was treated with NSAID whereas the use of csDMARDs was higher in peripheral SpA. The overall disease burden, as evaluated by patient’s and physician’s global assessment of disease activity as well as composite indices such as BASDAI and ASDAS, was higher in
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