Identification and characterization of new biochemical markers for sarcopenia

Abstract

Purpose: 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. 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. Methods: 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, Li ege, Belgium) on all collected samples. Results: There was no significant difference on Coll2-1 values between samples collected at any of the five sampling times (p¼0.85) or at any of the sampling days measured (p¼0.58). None of the sampling parameters tested had a significant impact on Coll2-1 value (clotting time, clotting temperature and temperature of blood centrifugation (p¼0.93), type of tube: p¼0.38) when all data from healthy subjects were pooled (n¼631 samples). On the contrary,subjects with knee OA had a significantly higher Coll2-1 concentration then healthy subjects (p<0,001). Conclusions: Coll2-1 is a biomarker of osteoarthritis measured using an immunoassay sufficiently robust for use in 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.

A Multifactorial Approach for Sarcopenia Assessment: A Literature Review

“…Studying aldolase A levels with MS spectrometry analysis, researchers found that a sarcopenia group had 4.2-fold higher levels than the control group. ELISA and Western blotting did not detect differential expression of full-length aldolase A, but fragments of the protein were detected as being differentially expressed [ 121 ]. Sex hormone-binding globulin is a glycoprotein involved in binding androgens and estrogens.…”

“…S100A8 are calcium- and zinc-binding proteins that regulate inflammation and immunity. Moreover, Western blot tests showed that sarcopenia patients had an enhanced detection of S100A8 [ 121 ].…”