Enzyme-linked immunoassay for plasma-free metanephrines in the biochemical diagnosis of phaeochromocytoma in adults is not ideal
Enzyme-linked immunoassay for plasma-free metanephrines in the biochemical diagnosis of phaeochromocytoma in adults is not ideal
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DOI：
10.1515/cclm.2011.742
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发表时间：
2012-01-01
影响因子：
6.8
通讯作者：
Tormey, William
中科院分区：
文献类型：
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作者：
Mullins, Fiona;O'Shea, Paula;Tormey, William
背景：本研究的目的是确定劳动诊断北（LDN） 2-Met血浆酶联免疫吸附试验分离血浆肾上腺素在嗜铬细胞瘤的生化诊断中的分析和诊断性能。方法：对所述生产厂家的性能特点进行评价。采用液相色谱串联质谱法（LC-MS/MS）评估临床应用的偏倚、敏感性和特异性结果。样本（n=73）来自已排除嗜铬细胞瘤（n=60）的患者（n=60），基于疾病的低概率，尿分离儿茶酚胺和肾上腺素的重复阴性检测，缺乏肿瘤的放射学和组织学证据，以及从组织学证实肿瘤的组（n=13）中收集。k(2)EDTA管采集的血液在30分钟内处理。分离的血浆在分析前被引用（x2）并在-40℃冷冻。一组用ldn2 - met酶联免疫吸附试验分析血浆肾上腺素，另一组用LC-MS/MS法分析血浆肾上腺素。结果：与参比法（LC-MS/MS）相比，去甲肾上腺素（ELISA）的平均偏差为-32%，可能导致嗜铬细胞瘤的漏诊。该方法的灵敏度（100%）与参比法相当，但特异性（88.3%）低于参比法（95%），对嗜铬细胞瘤的生化诊断不够理想。结论：劳动诊断协会（LDN） 2-Met酶联免疫吸附试验测量的血浆游离肾上腺素没有显示出支持其作为嗜铬细胞瘤生化检测筛选方案的一部分的测试特征，除非确定的校准问题得到纠正，并且其他更准确和分析特异性的方法仍然不可用。
Background: The aim of the study was to define the analytical and diagnostic performance of the Labor Diagnostica Nord (LDN) 2-Met plasma ELISA assay for fractionated plasma metanephrines in the biochemical diagnosis of phaeochromocytoma.Methods: The stated manufacturer's performance characteristics were assessed. Clinical utility was evaluated against liquid chromatography tandem mass spectrometry (LC-MS/MS) using bias, sensitivity and specificity outcomes. Samples (n=73) were collected from patients in whom phaeochromocytoma had been excluded (n=60) based on low probability of disease, repeat negative testing for urinary fractionated catecholamines and metanephrines, lack of radiological and histological evidence of a tumour and from a group (n=13) in whom the tumour had been histologically confirmed. Blood collected into k(2)EDTA tubes was processed within 30 min. Separated plasma was aliquoted (x2) and frozen at -40 degrees C prior to analyses. One aliquot was analysed for plasma metanephrines using the LDN 2-Met ELISA and the other by LC-MS/MS.Results: The mean bias of -32% for normetanephrine (ELISA) when compared to the reference method (LC-MS/MS) makes under-diagnosis of phaeochromocytoma likely. The sensitivity of the assay (100%) was equal to the reference method, but specificity (88.3%) lower than the reference method (95%), making it less than optimum for the biochemical diagnosis of phaeochromocytoma.Conclusions: Plasma-free metanephrines as measured by Labor Diagnostica Nord (LDN) 2-Met ELISA do not display test characteristics that would support their introduction or continuation as part of a screening protocol for the biochemical detection of phaeochromocytoma unless the calibration problem identified is corrected and other more accurate and analytically specific methods remain unavailable.