Development of immunoassays for serum tartrate-resistant acid phosphatase isoform 5a
Development of immunoassays for serum tartrate-resistant acid phosphatase isoform 5a
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DOI：
10.1016/j.cccn.2005.03.039
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发表时间：
2005-09-01
影响因子：
5
通讯作者：
Janckila, AJ
中科院分区：
文献类型：
--
作者：
Chao, TY;Lee, SH;Janckila, AJ
背景：血清抗酒石酸酸性磷酸酶（TRACP）由2个结构相关的异构体组成，即TRACP 5a和5b。TRACP 5b来自骨吸收破骨细胞。TRACP 5a可能是炎症的巨噬细胞产物。我们使用一种新的TRACP 5a抗体来标准化血清TRACP 5a活性和蛋白的免疫测定。方法：采用生物素化抗TRACP抗体固定化血清TRACP亚型。以4-硝基苯基磷酸为底物测定TRACP活性。用独立的过氧化物酶偶联抗TRACP抗体检测TRACP 5a蛋白。对血清剂量反应的线性、灵敏度和精密度进行标准化免疫测定。从50名健康男性和50名年龄匹配的健康女性血清中建立了TRACP 5a的参考范围。测定29例类风湿关节炎患者血清TRACP 5a活性及蛋白水平。结果：两种TRACP 5a检测的血清基质干扰需要稀释至10%血清才能接近线性。试验内和试验间CV% < 10%。健康男性的平均血清TRACP 5a活性和蛋白水平明显高于女性。20 - 70岁女性血清TRACP 5a和5b均有轻微但显著的年龄相关升高，而男性无。健康血清中TRACP 5a活性与TRACP 5a蛋白呈正相关。TRACP 5a活性和蛋白与TRACP-5b活性均无明显相关性。8/29 RA血清中TRACP 5a蛋白显著升高，而TRACP 5a和5b蛋白活性未见显著升高。RA血清中TRACP 5a活性与蛋白水平无显著相关性。结论：尽管TRACP 5a和5b是生物合成相关的，但它们在健康人体内的循环水平是独立的，表明它们的表达调控存在差异。在慢性疾病中，增加的TRACP 5a可能代表与骨代谢无关的炎症病理过程。Elsevier B.V.出版
Background: Serum tartrate-resistant acid phosphatase (TRACP) consists of 2 structurally related isoforms, TRACP 5a and 5b. TRACP 5b is from bone-resorbing osteoclasts. TRACP 5a may be a macrophage product of inflammation. We used a novel antibody to TRACP 5a to standardize immunoassays for serum TRACP 5a activity and protein.Methods: Biotinylated anti-TRACP antibodies were used to immobilize serum TRACP isoforms. TRACP activity was measured using 4-nitrophenyl phosphate as substrate. TRACP 5a protein was measured with an independent peroxidase-conjugated anti-TRACP antibody. Immunoassays were standardized for linearity of serum dose response, sensitivity and precision. Reference ranges for TRACP 5a were established from serum of 50 healthy males and 50 healthy age-matched females. Serum TRACP 5a activity and protein were determined in 29 cases of rheumatoid arthritis.Results: Serum matrix interference in both TRACP 5a assays required dilution to 10% serum to approach linearity. Intra-assay and inter-assay CV% were < 10%. Mean serum TRACP 5a activity and protein were significantly higher in healthy men than women. There was a slight, but significant age related increase in both serum TRACP 5a and 5b among females, but not males, from age 20 to 70 years. TRACP 5a activity was positively correlated to TRACP 5a protein in healthy sera. Neither TRACP 5a activity nor protein was correlated strongly to TRACP-5b activity. TRACP 5a protein was significantly increased in 8/29 RA sera, whereas TRACP 5a and 5b activities were not. TRACP 5a activity and protein were not significantly correlated in RA sera.Conclusions: Although TRACP 5a and 5b are related biosynthetically, their circulating levels in healthy humans were independent, suggesting differential regulation of expression. In chronic diseases, increased TRACP 5a may represent pathological processes of inflammation unrelated to bone metabolism. Published by Elsevier B.V.