Christgau S, Rosenquist C, Alexandersen P, Bjarnason N H, Ravn P, Fledelius C, Herling C, Qvist P, Christiansen C
Osteometer Biotech A/S, Osteopark, Herlev Hovedgade, Denmark.
Clin Chem. 1998 Nov;44(11):2290-300.
The Serum CrossLaps One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a beta-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen alpha1-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 CrossLaps 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.
血清交联C末端肽一步酶联免疫吸附测定法是一种夹心测定法，使用两种单克隆抗体，它们对源自I型胶原α1链羧基末端端肽区域的表位EKAHDGGR的β-天冬氨酸形式具有特异性。我们的目的是评估血清交联C末端肽测定法在监测骨质疏松症治疗中抗吸收治疗的临床价值。在血清交联C末端肽一步酶联免疫吸附测定法中，对从接受不同剂量的循环或连续激素替代疗法（HRT）、使用雌激素类似物（替勃龙）或双膦酸盐（伊班膦酸钠）治疗的绝经后妇女中获取的样本在基线时以及治疗期间的各个时间点进行测量。相应的尿液样本在尿液交联C末端肽酶联免疫吸附测定法中进行测量，并根据肌酐排泄量进行校正。血清交联C末端肽测量值与相应的尿液交联C末端肽测量值高度相关（所有研究中r>0.8）。在接受任何一种具有临床相关剂量抗吸收剂治疗的女性中，血清和尿液交联C末端肽测量值均显著下降。此外，骨矿物质密度（BMD）的年度百分比变化与交联C末端肽浓度的测量变化相关。血清交联C末端肽测定法在评估BMD变化时显示出83 - 100%的特异性和59 - 83%的敏感性。肌酐校正后尿液测量值的相应数值为83 - 92%的特异性和68 - 79%的敏感性。我们得出结论，便捷的血清交联C末端肽一步酶联免疫吸附测定法的性能在骨质疏松症抗吸收治疗随访方面至少与尿液检测相当。需要进一步研究以优化其在这一及其他临床应用中的使用。
