SAT0276 Change of Asdas Over 3 Months is a Good Predictive Factor for Improvement of Metrology Index After Long-Term Treatment with TNF-Blockers in Ankylosing Spondylitis

BackgroundAnkylosing spondylits (AS) is a chronic inflammatory spondyloarthritis characterized by prominent axial ankylosis, peripheral arthritis, and enthesopathy. The Bath Ankylosing Spondylitis Metrology Index (BASMI), a metrologic assessment of spinal mobility, is well correlated with the change of spinal inflammation and soft tissue involvement. The Ankylosing Spondylitis Disease Activity Score (ASDAS), which incorporates the CRP or ESR values in addition to patient-reported outcome (PRO) measurements, is a new composite index to assess disease activity in AS. However, ASDAS as a predictive factor for the metrologic improvement in AS patients treated with TNF-blockers is still largely unknown.ObjectivesTo investigate whether ASDAS is a valuable predictive factor for the metrologic outcome in AS patients treated with long-term treatment with TNF-blockers.MethodsA retrospective study was conducted in a total of 113 patients who were treated with TNF-blockers (126 cases; 100 patients with single agent and 13 patients with two). Clinical efficacy was assessed using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), patient's global assessment (PtGA), physician's global assessment (PhGA), pain, ASAS response criteria (ASAS20, ASAS40, ASAS5/6), BASDAI50, acute phase reactants (ESR, CRP), ASDAS, and BAMI10 at baseline and month 3, and then every six months up to month 33.ResultsMean age was 34.3±9.9 years and 89.4% was male. Three TNF-α blockers including etanercept (57 cases), adalimumab (56 cases), and infliximab (13 cases) showed a similar clinical efficacy. BASMI10, which reflects the spinal mobility, showed a significant improvement at month 33 compared to baseline (3.3±2.4 vs. 4.3±2.4, p