Raber Wolfgang, Kotal Hans, Marculescu Rodrig, Scheuba Christian, Niederle Martin B, Kautzky-Willer Alexandra, Krebs Michael
Division of Endocrinology & Metabolism, Department of Medicine III, Medical University of Vienna, 1090 Vienna, Austria.
Department of Laboratory Medicine, Medical University of Vienna, 1090 Vienna, Austria.
J Clin Med. 2020 Sep 26;9(10):3108. doi: 10.3390/jcm9103108.
Studies conflict concerning the use of enzyme immunoassays (EIA) for plasma free metanephrines (P-MNs) vs. other methods for pheochromocytoma/paraganglioma (PPGL) diagnosis. We compared commercially available EIAs for P-MNs with high-pressure liquid chromatography (HPLC) for 24 h-urinary MNs (U-MNs) and -catecholamines (U-CATs). 943 (565 female, 378 male) patients (54 PPGL, 889 Non-PPGL) were studied. Simultaneous measurements of all parameters analyzed at the central lab of our university hospital was mandatory for inclusion. Sensitivity of P-MNs (94.4%) was similar to that of U-MNs (100%), and both were higher than of U-CATs (77.8%), specificity of P-MNs (100%) higher than of U-MNs (73.6%), and similar to U-CATs (99.8%). With the recently proposed downward adjusted ULN of P-MNs to correct for the reported negative bias of the EIAs sensitivity (98.1%) raised non-significantly, but specificity decreased significantly (94.8%). Areas under receiver-operating characteristic curves indicated comparable diagnostic performance of P-MNs (0.989) vs. U-MNs (0.995), both better than U-CATs (0.956). In summary, the EIAs to measure P-MNs performed similarly to U-MNs by HPLC, and both better than U-CATs by HPLC. The post-test probability of PPGL given a positive test result was best for P-MNs, and higher than for the other pairs of analytes. Downward corrections of ULN of P-MNs did not improve test performances.
关于使用酶免疫测定法（EIA）检测血浆游离甲氧基肾上腺素（P-MNs）与其他方法诊断嗜铬细胞瘤/副神经节瘤（PPGL）的研究结果存在冲突。我们将市售的P-MNs EIA与用于检测24小时尿甲氧基肾上腺素（U-MNs）和尿儿茶酚胺（U-CATs）的高压液相色谱法（HPLC）进行了比较。研究了943例患者（565例女性，378例男性）（54例PPGL，889例非PPGL）。纳入研究的患者必须在我们大学医院中心实验室同时测量所有分析参数。P-MNs的灵敏度（94.4%）与U-MNs的灵敏度（100%）相似，且两者均高于U-CATs的灵敏度（77.8%）；P-MNs的特异性（100%）高于U-MNs的特异性（73.6%），与U-CATs的特异性（99.8%）相似。随着最近提出的P-MNs ULN向下调整以校正报道的EIA灵敏度负偏差，灵敏度（98.1%）无显著提高，但特异性显著降低（94.8%）。受试者工作特征曲线下面积表明P-MNs（0.989）与U-MNs（0.995）的诊断性能相当，两者均优于U-CATs（0.956）。总之，检测P-MNs的EIA与HPLC法检测U-MNs的性能相似，且两者均优于HPLC法检测U-CATs。检测结果为阳性时，PPGL的检测后概率以P-MNs最高，且高于其他分析物对。P-MNs ULN的向下校正并未改善检测性能。
