AB0092 SERUM LEVELS OF COLL2–1, A SPECIFIC BIOMARKER OF CARTILAGE DEGRADATION, ARE NOT AFFECTED BY SAMPLING CONDITIONS, CIRCADIAN RHYTHM, SEASONABILITY AND PHYSICAL ACTIVITY
Authors: Yves Henrotin, Berenice Costes, Elisabeth Cobraiville, Sebastien Pirson, Anne-Christine Hick
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Coll2-1 is a nine amino acid sequence (HRGYPGLDG) specific of type II collagen which is released during cartilage degradation. This peptide is located in the triple helicoidal part of type II collagen molecule(1,2,3). <h3>Objectives</h3> This study aims to assess intra-individual biological variability of serum cartilage specific biomarker Coll2-1 and define the best standardized conditions for blood sampling in clinical trials. <h3>Methods</h3> Blood samples were taken from 122 subjects with diagnosed knee osteoarthritis (KOA) at a single timepoint as well as from 15 healthy subjects under various conditions, including fasting condition (before or after breakfast and lunch), sampling time (at 8am, 9am, 12pm, 2pm and 5pm), sampling season (at baseline and after 2, 16, 52 and 68 weeks), physical activity (after a resting weekend versus working day), blood treatment (blood clotting from 1h to 24h at room temperature or 4°C; centrifugation at room temperature or 4°C) and type of blood collection tube (dry tube versus dry tube with gel separator). Type II collagen-specific biomarker Coll2-1 was measured using ELISA (Artialis Groups SA, Liège, Belgium) on all collected samples. <h3>Results</h3> There was no significant difference on Coll2-1 values between samples collected at any of the five sampling times (p=0.85) or at any of the sampling days measured (p=0.58). None of the sampling parameters tested had a significant impact on Coll2-1 value (clotting time, clotting temperature and temperature of blood centrifugation (p=0.93), type of tube: p=0.38) when all data from healthy subjects were pooled (n=631 samples). On the contrary,subjects with knee OA had a significantly higher Coll2-1 concentration then healthy subjects (OA: 481+/-144nM vs Healthy 192+/-32nM, p&lt;0,001). <h3>Conclusion</h3> Coll2-1 assay is sufficiently robust for use during OA clinical trials. Coll2-1 measurement is not affected by subject specific conditions such as fasting, resting state, circadian rhythm, seasonality, nor by sampling process factors such as type of dry tube, clotting patterns and centrifugation temperature. <h3>References</h3> [1] Henrotin Y, Addison S, Kraus V, Deberg M: Type II collagen markers in osteoarthritis: what do they indicate?Curr Opin Rheumatol2007, 19:444–450. [2] Henrotin Y, Deberg M, Dubuc JE, Quettier E, Christgau S, Reginster JY: Type II collagen peptides for measuring cartilage degradation. Biorheology2004, 41:543–547. [3] Henrotin Y, Sanchez C, Cornet A, Van de Put J, Douette P, Gharbi M : Soluble biomarkers development in osteoarthritis: from discovery to personalized medicine. Biomarkers 2016, 20:8, 540-546. <h3>Disclosure of Interests</h3> Yves Henrotin Shareholder of: Artialis SA, Berenice Costes Employee of: Artialis SA, Elisabeth Cobraiville Employee of: Artialis SA, Sebastien Pirson Employee of: Artialis SA, Anne-Christine Hick Employee of: Artialis SA