Pizzolo F, Salvagno G, Caruso B, Cocco C, Zorzi F, Zaltron C, Castagna A, Bertolone L, Morandini F, Lippi G, Olivieri O
Unit of Internal Medicine, Department of Medicine, University of Verona, Verona, Italy.
Laboratory of Clinical Biochemistry, Department of Life and Reproduction Sciences, University of Verona, Verona, Italy.
J Hum Hypertens. 2017 Dec;31(12):826-830. doi: 10.1038/jhh.2017.62. Epub 2017 Aug 24.
Aldosterone and renin measurement is a cornerstone for primary aldosteronism (PA) diagnosis, but different thresholds are used according to different assays. A fully automated chemiluminescence (CL) immunoassay for renin and aldosterone was recently proposed, showing good performance for PA screening by aldosterone to renin ratio (ARR). This study aimed to define the accuracy of this assay in the screening and in the most popular confirmatory test of autonomous aldosterone production, the intravenous saline loading test (ivSLT). We compared aldosterone results obtained by CL vs radioimmunoassay (RIA) in hypertensive patients investigated for PA (102 baseline and 85 after ivSLT). An excellent correlation was observed between RIA and CL in the entire population for aldosterone (r=0.922) and ARR (r=0.977). For ARR, Deming regression proved a good accordance between methods and, consistent with the fit model, our previous institutional ARR cut-off of 32 (pg ml)/(pg ml) corresponded to 20 pg ml mU l in CL assay. However, the correlation was weaker in the low end of aldosterone concentrations (r=0.676 for aldosterone <100 pg ml), with a concordance of ivSLT results in only 68% of patients. CL assay displays a diagnostic performance very similar to RIA for ARR screening, but it is substantially inferior in the setting of confirmatory tests of autonomous aldosterone secretion, that is, ivSLT.
醛固酮和肾素检测是原发性醛固酮增多症（PA）诊断的基石，但根据不同检测方法会使用不同的阈值。最近提出了一种用于肾素和醛固酮的全自动化学发光（CL）免疫测定法，该方法通过醛固酮与肾素比值（ARR）对PA筛查显示出良好性能。本研究旨在确定该检测方法在自主醛固酮分泌筛查以及最常用的确认试验——静脉盐水负荷试验（ivSLT）中的准确性。我们比较了在因PA接受检查的高血压患者中（102例基线和85例ivSLT后）通过CL法与放射免疫测定法（RIA）获得的醛固酮结果。在整个人群中，RIA与CL法在醛固酮（r = 0.922）和ARR（r = 0.977）方面观察到极好的相关性。对于ARR，Deming回归证明两种方法之间具有良好的一致性，并且与拟合模型一致，我们之前机构设定的ARR临界值32（pg ml）/（pg ml）在CL检测中对应于20 pg ml mU l。然而，在醛固酮浓度较低端相关性较弱（醛固酮<100 pg ml时r = 0.676），ivSLT结果的一致性仅为68%的患者。CL检测在ARR筛查方面显示出与RIA非常相似的诊断性能，但在自主醛固酮分泌的确认试验即ivSLT中则明显较差。
