Comparison of ID-LC-MS/MS and two CLIAs in measuring plasma aldosterone / 中华检验医学杂志

ABSTRACT

Objective Accurate measurement of aldosterone is critical in the diagnosis of primary aldosteronism. We compared the harmonization of three assays including isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and two chemiluminescence immunoassays (CLIAssystem A and system B) for the aldosterone measurement. Methods A total of 45 plasma samples, 4 quality control materials, 5 lyophilized bovine serums, and 3 fresh frozen human serum pools were measured by three assays respectively. Based on CLSI EP15-A3 rule, the precision was assessed by coefficient of variance. Deming regression and Bland&Altman plots was performed for method comparison, and correlation coefficient was calculated for concordance (CCC). Results All three methods met the performance criteria based on desirable biological variation for precision (<7.35％). System A showed a relevantly good correlation and comparability with ID-LC/MS/MS (R2=0.985, CCC=0.967), while System B showed relevantly bad correlations and comparability with both System A (R2=0.538, CCC=0.605) and ID-LC/MS/MS (R2=0.547, CCC=0.528).. However, the average relevant bias of two CLIAs exceeded the bias requirement derived from biological variation (18.60％). Conclusion Significant differences were found in the measurement of plasma aldosterone using ID-LC-MS/MS and two CLIAs, which urges the establishment of traceability hierarchy and improvement of reagents' specificity for standardization of aldosterone measurement in clinical settings.