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Updated: Sep 10, 2025
Peptide and Protein Quantification Using Automated Immuno-MALDI iMALDI
Published on: August 18, 2017
An innovative immunoassay for accurate aldosterone quantification: overcoming low-level inaccuracy and renal
Kaijuan Wang1, Hongying Cong1, Zhangwei Gao1
1Center of Laboratory Medicine, Beijing Key Laboratory of Cardiovascular Disease Warning and Diagnosis, National Clinical Research Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College/National Center for Cardiovascular Diseases, Beijing, China.
Objectives:
Accurate quantification of aldosterone is critical for screening and diagnosing primary aldosteronism (PA). Current competitive chemiluminescence immunoassays (cCLIA) overestimate plasma aldosterone concentration (PAC) compared to liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, LC-MS/MS is technically demanding and time-consuming, limiting its widespread clinical utility. Therefore, a novel two-step sandwich chemiluminescence immunoassay (sCLIA) for accurate quantification of PAC was systematically evaluated.
Methods:
Precision, trueness, linear range, and maximum dilution factor of the new immunoassay were comprehensively validated. In a multicenter study involving 2,696 samples from seven Chinese centers, PAC measurements were performed in parallel using sCLIA, cCLIA, and LC-MS/MS. The study specifically focused on evaluating the assay's performance at low aldosterone concentrations and in patients with chronic kidney disease (CKD), investigating potential interference from renal impairment by comparing the consistency between immunoassays and LC-MS/MS results across different CKD stages.
Results:
The sCLIA exhibited excellent analytical performance for PAC measurement, with intra-assay imprecision <4.64 % and bias <5.71 % against certificated reference materials. The assay exhibited a wide reportable range (30-100,000 ng/L) with a limit of quantification at 30 ng/L and dilution capability ≥50-fold. Compared to cCLIA, sCLIA showed superior agreement with LC-MS/MS, particularly at low PAC concentrations (<110 ng/L) and in subjects with reduced renal function (eGFR<60 mL/min/1.73 m2).
Conclusions:
This novel sCLIA method exhibited excellent analytical performance, combining the practical advantages of immunoassays with LC-MS/MS accuracy, thereby offering an ideal solution for large-scale primary aldosteronism screening in clinical practice.
