POS0809 A BIOMARKER PROFILE AIDING AN EARLY DIAGNOSIS OF GIANT CELL ARTERITIS

Background: Diagnosing patients with giant cell arteritis (GCA) remains difficult. Due to its non-specific symptoms, it is challenging identify GCA in presenting polymyalgia rheumatica (PMR), which a more common disease (1). In addition, commonly used acute-phase markers fail discriminate between and (infectious) mimicry patients. Objectives: To investigate selection of biomarkers for their utility the accurate diagnosis two cohorts. Methods: Treatment-naïve participated Aarhus GCA/PMR cohort (N=52) Groningen GPS (N=48). Symptoms biomarker levels were compared phenotypically as isolated PMR, controls healthy (HCs). Diagnosis or exclusion was based on clinical assessment majority cases aided by imaging. Serum/plasma 12 measured ELISA Luminex. Results: both cohort, we found that weight loss, elevated erythrocyte sedimentation rate (ESR) higher angiopoietin-2/-1 ratios but lower matrix metalloproteinase (MMP)-3 concomitant PMR (Figure 1). confirmed (1) platelet counts are characteristic not look-alikes, low MMP-3 proteinase 3 (PR3) may help from other diseases Multiple inflammation patient control groups when HCs. Conclusion: This study, performed independent cohorts, consistently shows potential PMR. These be select require further diagnostic workup. Platelet look-alike Figure 1. Summary most important consistent findings A four factors perform best discriminating overlap B Cut-off values calculated Youden index. References: [1]van der Geest, KSM, Sandovici M, Brouwer E, Mackie SL. Diagnostic accuracy physical signs, laboratory tests arteritis: systematic review meta-analysis. JAMA internal medicine. 2020. Disclosure Interests: Yannick van Sleen: None declared, Philip Therkildsen: Annemieke Boots: Berit Dalsgaard NIelsen: Kornelis Geest: Peter Heeringa: Minke G. Huitema: M.D. Posthumus: Maria Sandovici: Erik Toonen Employee of: Is an employee Hycult Biotech, Jannik Zijlstra: Ellen-Margrethe Hauge: Elisabeth Brouwer: declared