Analytical evaluation of the Snibe β-isomerized C-terminal telopeptide of type i collagen (β-CTX-I) automated method

Abstract

Bone is a dynamic tissue that undergoes constant remodeling, serving crucial roles in mechanical support, organ protection, locomotion, blood cell production, and mineral homeostasis [1]. Remodeling involves osteoclasts degrading old bone via proteolytic enzymes and osteoblasts synthesizing matrix proteins like osteocalcin and collagen [2]. Osteoporosis, a common bone metabolism disorder, manifests as low bone mass, microarchitectural deterioration, fragility, and fracture susceptibility [3]. Bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) is commonly used to diagnose osteoporosis and monitor osteoporosis treatment. Increases in BMD after treatment are correlated with a reduction of fracture risk. Apart from BMD there are other skeletal properties, collectively called ‘bone quality’, that also determine bone strength and fracture risk. Clinical trials have shown that reduction in fracture risk associated with anti-resorptive therapy may occur independently of changes in BMD [4]. For complete assessment of bone strength, BMD should be combined with assessments of bone quality. One important contributor of BMD and bone strength is the rate of bone remodeling, which can be assessed by measurement of bone turnover markers (BTMs). Bone turnover markers are products of osteoblasts (bone formation markers) and osteoclasts (bone resorption markers) providing a dynamic assessment of bone remodeling (bone turnover). The International Osteoporosis Foundation and the International Federation of Clinical Chemistry propose serum procollagen type I N propeptide (s-PINP) and C-terminal cross-linking telopeptide of type I collagen (CTx) as complementary markers for faster bone health trend assessment [5]. However, BTMs interpretation challenges arise from biological variability and lack of standardization [6]. To address this, our study aims to compare a newly available chemiluminescent assay for β-CTx with the currently used electrochemiluminescent method...