Serum Levels of Coll2-1, a Specific Biomarker of Cartilage Degradation, Are Not Affected by Sampling Conditions, Circadian Rhythm, and Seasonality

Abstract

Objective: To assess intraindividual biological variability of serum cartilage specific biomarker Coll2-1 and define the best standardized conditions for blood sampling.

Design: Blood samples were taken from 116 subjects with knee osteoarthritis (OA) at a single time point (PRODIGE study) and from 15 healthy subjects under various conditions, including fasting condition, sampling time and season, blood treatment, and type of blood collection tube (COVAR study). Type II collagen-specific biomarker Coll2-1 was directly measured in serum using an immunoassay.

Results: There was no significant difference on Coll2-1 values between samples collected at any of the 5 sampling times or at any of the sampling days measured. None of the sampling parameters tested had a significant impact on Coll2-1 value (clotting time, clotting temperature and temperature of blood centrifugation, type of tube). On the contrary, differences were found in between subjects and between subjects with knee OA and healthy subjects.

Conclusion: Coll2-1 measurement is not affected by sampling specific conditions, circadian rhythm or seasons but was found elevated in subject with knee OA indicating that Coll2-1 serum variation is not linked to the study environment, but to cartilage degradation in OA. Coll2-1 assay is sufficiently robust for use in OA clinical trials.

Trial registration: ClinicalTrials.gov NCT02070224.

Keywords: biomarkers; cartilage; clinical study; knee; osteoarthritis.

Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: YH is the founder and the President of ARTIALIS SA, Spin-off Company of the University of Liege. He has also received fees from Bepharbel, GSK, KiOmed Pharma SA (formerly Synolyne Pharma SA), Nestle, Flexion therapeutics, IBSA, BioIberica, Laboratoires Expanscience, Royal canin, MagPharm, LABRHA, Pfizer, Thuasne, and Tilman SA. ACH, BC, EC, SP, LG, AL and SV are employees of ARTIALIS S.A.

Figures

Figure 1.

Participant flow diagrams of COVAR study (left) and PRODIGE study (right).

Figure 2.

Coll2-1 serum concentrations (nM) at different times of the day (A), at different days (B), with different clotting parameters (C), with different centrifugation temperatures (D) and from different types of clotting tubes (E). No significative difference (P> .05). Boxplots are built with minimum, lower quartile (Q1), median, upper quartile (Q3) and maximum values. ♦indicates the mean and • are outliers.

Figure 3.

Coll2-1 serum concentration (nM) across all healthy subjects (significant subject association, P < 0.001). Dotted line represents the mean for all subjects. Boxplots are built with minimum, lower quartile (Q1), median, upper quartile (Q3) and maximum values. ♦indicates the mean and • are outliers.

Figure 4.

Coll2-1 serum concentration (nM) in healthy and knee osteoarthritis (OA) populations. Significative difference between the 2 groups (***P < 0.001). Boxplots are built with minimum, lower quartile (Q1), median, upper quartile (Q3) and maximum values. ♦indicates the mean and • are outliers.