POS0955 EXTRACELLULAR MATRIX PROTEIN TURNOVER MARKERS ARE ASSOCIATED WITH axSpA – A COMPARISON WITH CONTROL SUBJECTS WITH OR WITHOUT PELVIC, BUTTOCK OR BACK PAIN

Background: Axial spondyloarthritis (axSpA) is a common chronic inflammatory disease, associated with extracellular matrix (ECM) remodeling of the cartilage, bone and connective tissues. The primary symptom axSpA back pain, caused by inflammation. However, there medical need to truly identify patients from other subjects buttock or low pain attributable reasons. Tissue-derived markers quantified in serum may serve differentiate diagnostic entities. Objectives: To investigate circulating ECM turnover as potential biomarkers control group pelvic attributed reasons, including postpartum women healthy subjects. Methods: Biomarkers degradation/chronic inflammation (C1M, C3M, C4M, C6M, CRPM, C10C COL10NC) formation (PRO-C3 PRO-C6) were measured 204 participants MASH study [1] (Table 1). Biomarker levels compared among group, two new variables (Type 3 Type 6) included, corresponding index formation/degradation type III VI collagen respectively. biomarker data was log10 transformed for normalization when necessary linear regression models pairwise comparisons performed. Clinical scores SPARCC MRI sacroiliac joint (SIJ) correlated (data not shown). Table 1. Comparison blood-tested study. Data adjusted confounders age, gender, body mass (BMI). (Mean (SD)) Patients (n = 41) Control groups (n=163) p C1M 84.3 (85.8) 36.2 (22.1) <0.0001 C3M 15.6 (4.0) 13.9 (3.0) 0.011 C4M 34.9 (10.2) 27.9 (7.7) C6M 20.5 (5.8) 17.4 (4.2) CRPM 11.9 (2.9) 11.0 (5.9) 0.027 2567 (462) 2568 (560) 0.31 COL10NC 9.15 (5.81) 9.43 (8.27) 0.43 PRO_C3 10.2 (2.5) 11.3 0.0052 PRO_C6 6.94 (2.45) 6.86 (2.53) 0.93 (PRO-C3/C3M) 0.70 (0.28) 0.86 (0.31) 0.0004 6 (PRO-C6/C6M) 0.36 (0.16) 0.41 (0.14) 0.0024 Results: We found that had significantly increased MMP-mediated degradation I (C1M), (C3M), IV (C4M) (C6M) collagens (p<0.0001, p=0.01,p<0.001,p<0.001, respectively), CRP-metabolite (CRPM, p=0.027), decreased (p= 0.052) adjusting gender Significantly rates also observed (p=0.004, p=0.002, respectively). further analyses SIJ since differences these [1], similar found, indicating relationship between level independent groups. Conclusion: I, III, V showed an altered without Such be used combination independently separate conditions. References: [1]Seven, S., Østergaard, M., Morsel-Carlsen, L., Sørensen, I. J., Bonde, B., Thamsborg, G., ... & Pedersen, S. J. (2019). Magnetic Resonance Imaging Lesions Sacroiliac Joints Differentiation With Spondyloarthritis From Subjects Without Pelvic Buttock Pain: A Prospective, Cross-Sectional Study Participants. Arthritis Rheumatology, 71(12), 2034-2046. Acknowledgements: supported Innovation Fund Denmark, Rigshospitalet Danish Rheumatism Association (grant no. R102-A2132-B98, R159-A5061 R150-A4467-B98). Disclosure Interests: Helena Port Employee of: Industrial PhD student at Nordic Bioscience University Copenhagen, Signe Holm Nielsen Full time employee Bioscience, Joseph Blair Sofie Falkenløve Madsen A/S, Anne-Christine Bay-Jensen Shareholder Morten Karsdal Sengül Seven: None declared, Inge Juul Sørensen: Lone Morsel-Carlsen: Mikkel Østergaard: Susanne Juhl Pedersen: declared