Background It has been shown in the past that elevated C-reactive protein (CRP)  and the composite Ankylosing Spondylitis Disease Activity Score (ASDAS) [2,3] are associated with radiographic spinal progression in axial spondyloarthritis (axSpA). It is not clear, however, whether patient-reported measures of disease activity might also play a predictive role.
Objectives To investigate the association between patient-reported measures of disease activity and radiographic spinal progression over two years in early axSpA.
Methods Altogether 178 patients with definite axSpA (100 with ankylosing spondylitis and 78 with non-radiographic axSpA) from the German Spondyloarthritis Inception Cohort (GESPIC) were included in the current study. Spinal radiographs (cervical spine lateral views, lumbar spine lateral and anteroposterior views) were scored according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) system and for the presence of syndesmophytes. Clinical and lab data were collected at baseline and every 6 months thereafter. Time-averaged values (over 2 years) of the patient global assessment of disease activity (PG), BASDAI and its components, CRP and CRP-based ASDAS, were calculated.
Results In the logistic regression analysis there was a significant association between time-averaged patient global and syndesmophyte formation (table): the adjusted odds ratio (OR) was 1.30 (1.01–1.69) meaning a 30% increase of the chance for new syndesmophytes formation over two years with an increase of PG by 1 point (on a 0–10 scale). The time-averaged BASDAI demonstrated no significant association with radiographic spinal progression, but duration and severity of morning stiffness were both significantly associated with syndesmophytes formation with a similar strength of association as the patient global (table). Similar trends although not always significant were observed for the mSASSS worsening by 2 points and more after two years. CRP and ASDAS did show an already known association with radiographic spinal progression in early axial SpA.
Conclusions Higher patient global assessment of disease activity, duration and severity of morning stiffness are clinical parameters, which are associated with more radiographic spinal progression (syndesmophytes formation) in patients with early axial spondyloarthritis.
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Disclosure of Interest None declared