AB0860 Acute phase reactant change in ankylosing spondylitis patients

BackgroundThe aim of this study is to investigate the levels of acute phase reactants (APRs) in patients with ankylosing spondylitis (AS) at the time of diagnosis and during follow-up. We also evaluated the associations between APR levels and disease activity.MethodsThe study included 948 patients with AS who were followed-up at Dokuz Eylul University School of Medicine Rheumatology outpatient clinic. The patients’ erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels across all visits were retrospectively reviewed through the Turkbio registry and the hospital’s database. Disease activity and follow-up parameters as BASDAI, ASDAS, BASFI and BASMI were taken from Turkbio visit charts. The correlation between APR and follow-up parameters were evaluated with Spearman correlation coefficient analysis.ResultsThere were 948 AS patients (69% male, mean age 46,6±12,1 years) who fulfilled the 1984 modified New York criteria. At first visit, high levels of CRP and ESR were observed in 626 (68.5%) and 578 (64.6%) patients respectively. During follow-up 84.6% of patients had high CRP and 69.5% patients had high ESR at any visit (figure 1). However in 10% of AS patients APRs did not increase at any visits. There was good correlation between ESR and CRP (r=0.666, p<0.001). A better correlation was observed at first visit between CRP and BASDAI (r=0.81, p=0.23) or ASDAS (r=0.468, p<0.001) compared to ESR and BASDAI (r=0.111, p=0.02) or ASDAS (r=0.334, p<0.001) (table 2). Compared to BASDAI, ASDAS with either ESR (p<0.001) or CRP (very high disease activity-p <0.001, inactive disease-p=0.001) had better performance in evaluating the activity of the patient in inactive and very high levels of severe disease (table 2).ConclusionsIn over 80% patients with AS had elevated levels of CRP, the most frequently used laboratory parameter, during follow-up. CRP is well correlated with ESR, and disease activity parameters as BASDAI, ASDAS, BASFI and BASMI. Compared to BASDAI; ASDAS had better agreement between activity and APRs. Interestingly, in 10% of AS patients APRs did never increase in follow-up.Disclosure of InterestNone declared