[Laboratory evaluation of bone metabolism index using elecsys 2010.].
BACKGROUND
Bone markers can provide a prognostic information about the risk of osteoporotic fracture and are useful tools for monitoring the efficacy of antiresorptive therapy. We evaluated the analytical performance of the bone markers of Elecsys 2010 (Roche Diagnostics Corp., Indianapolis, USA).


METHODS
We evaluated the analytical performance of the Elecsys 2010 for serum parathyroid hormone (PTH), osteocalcin, and serum bone-derived degradation products of type I collagen C-telopeptide (S-CTX) using control material and patients' specimens. For the comparison studies, an immunoradiometric assay was used for PTH and an ELISA for serum osteocalcin and serum bone-derived degradation products of type I collagen N-telopeptide (S-NTX). We established the reference intervals of S-CTX and serum osteocalcin by analyzing 4569 Korean healthy subjects according to sex and age.


RESULTS
Within-run and total CV of most items were below 5% except S-CTX low level (5.42%). Elecsys 2010 showed a good linearity (r>/=0.99, P<0.01). Good correlations with other methods were found in osteolcalcin (r=0.95, P<0.01) and PTH (r=0.96, P<0.01). S-CTX showed a good correlation with S-NTX (r=0.76, P<0.01). Reference intervals of serum osteocalcin (ng/mL) and S-CTX (ng/mL) were 9.58-33.62 and 0.18-0.89, respectively, in adult male, 8.00-31.46 and 0.11-0.81 in 31-50 years old female, and 8.30-43.50 and 0.11-1.00 in 51-80 years old female.


CONCLUSIONS
Elecsys 2010 bone markers showed a satisfactory precision, linearity, and a good correlation with other methods. With its 'one system-many capabilities' features, Elecsys 2010 would be a useful tool for measuring bone metabolism indices.