Tartrate-resistant acid phosphatase 5b:: A novel serum marker of bone resorption
Tartrate-resistant acid phosphatase 5b:: A novel serum marker of bone resorption
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DOI：
10.1359/jbmr.2000.15.7.1337
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发表时间：
2000-07-01
影响因子：
6.2
通讯作者：
Väänänen, HK
中科院分区：
文献类型：
--
作者：
Halleen, JM;Alatalo, SL;Väänänen, HK
人血清含有两种形式的抗酒石酸酸性磷酸酶（TRAP），5a和5b，其中5a含有唾液酸，5b不含。我们在这里表明，从人破骨细胞中纯化的TRAP的抗原特性和pH最佳值是相同的血清TRAP 5b和完全不同的血清TRAP 5a，这表明5b将来自破骨细胞和5a从一些其他来源。我们使用单克隆抗体O1A作为捕获抗体开发了一种新的特异性5b免疫测定法。O1A不结合血小板和红细胞来源的酸性磷酸酶。Western分析表明，O1A对人骨和血清中的TRAP具有特异性。我们在pH 6.1下测量了结合的TRAP活性，其中5b是高度活性的，5a几乎完全无活性。在25 ℃下孵育血清样品8小时后和在4 ℃下孵育3天后，免疫测定检测到超过90%的初始TRAP 5b活性。与接受安慰剂的绝经后妇女中观察到的变化相比，绝经后妇女的激素替代疗法（HRT）6个月后血清TRAP 5b活性显著降低（p < 0.0001）。相反，在安慰剂组和HRT组的总血清TRAP量的变化之间没有观察到显著差异。这些结果表明，血清TRAP 5b是监测抗吸收治疗的特异性和敏感性标志物。相反，总血清TRAP不能用于该目的。这些发现可能是使用血清TRAP作为吸收标志物的显著改善。
Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b, Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP activity at pH 6.1, where 5b is highly active and 5a almost completely inactive. The immunoassay detected more than 90% of the initial TRAP 5b activity after 8-h incubation of serum samples at 25 degrees C and after 3 days incubation at 4 degrees C, Serum TRAP 5b activity decreased significantly after 6 months of hormone replacement therapy (HRT) of postmenopausal women compared with the change observed in postmenopausal women receiving placebo (p < 0.0001). Instead, no significant differences were observed between the changes in the placebo and HRT groups in total serum TRAP amount. These results show that serum TRAP 5b is a specific and sensitive marker for monitoring antiresorptive treatment. Instead, total serum TRAP cannot be used for that purpose. These findings may turn out to be a significant improvement in using serum TRAP as a resorption marker.