Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides

Abstract

The Serum CrossLapsTM One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a β-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen α1-chain. Our objective was to assess the clinical value of the Serum CrossLaps assay for monitoring antiresorptive therapy in osteoporosis treatment. Samples obtained from postmenopausal women treated with different doses of cyclic or continuous hormone replacement therapy (HRT) with an estrogen analog (tibolone) or with a bisphosphonate (ibandronate) were measured in the Serum CrossLaps One Step ELISA at baseline and at various time points during therapy. The corresponding urine samples were measured in the urine CrossLapsTM ELISA and corrected for creatinine excretion. The serum CrossLaps measurements and corresponding urinary CrossLaps measurements were highly correlated (r >0.8 for all studies). The serum and urine CrossLaps measurements showed a significant decrease among the women treated with clinically relevant doses of either of the antiresorptive agents. Furthermore, the annual percentage change in bone mineral density (BMD) correlated with the measured changes in CrossLaps concentration. The serum CrossLaps assay showed a specificity of 83–100% and a sensitivity of 59–83% for assessing BMD changes. The corresponding values for the creatinine-corrected urinary measurements were 83–92% specificity and 68–79% sensitivity. We conclude that performance of the convenient Serum CrossLaps One Step ELISA is at least equivalent to that of the urine text for follow up of antiresorptive treatment in osteoporosis. Further studies are needed to optimize its use in this and other clinical applications.

Bone turnover markers and sex hormones in men with idiopathic osteoporosis

“…CTX excretion was similar in both groups. Recently, an ELISA for the determination of CTX in human serum has been developed; in clinical studies serum CTX performed at least equivalent to the urinary test [19,20]. Also in our study, serum CTX turned out to be a sensitive indicator for osteoclastic bone resorption (Table 3; cf.…”

Using biochemical markers of bone turnover in clinical practice

“…Several other assays target structural variants of a peptide sequence that originates from the carboxy-terminal cross-linking region of collagen type I (CTx). 12,13 Other markers of bone resorption Two enzymes found in osteoclasts have received attention as markers of osteoclast activity.…”

Safety and Efficacy of a Novel Salmon Calcitonin (sCT) Technology-Based Oral Formulation in Healthy Postmenopausal Women: Acute and 3-Month Effects on Biomarkers of Bone Turnover

“…Concentration of CTx in the urine and serum was estimated by ELISA (Serum and Urinary Cross-Laps One Step ELISA; Osteometer Biotech, Herlev, Denmark). (12) Serum OC was also measured by ELISA (twosite N-mid osteocalcin ELISA; Osteometer BioTech, Denmark). (13) Serum PTH and calcium were measured by an automatic blood analyzers, Elecsys 2010 and Hitachi 912 (Roche Diagnostics, Mannheim, Germany), respectively.…”