PS-C21-10: A LC-MS/MS-EQUIVALENT VALUE OF ALDOSTERONE MEASUREMENT BY A NEW CHEMILUMINESCENT ENZYME IMMUNOASSAY USING A TWO-STEP SANDWICH METHOD

Abstract

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension. Patients with PA have an increased risk of cardiovascular events, such as cerebral infarction, myocardial infarction, and chronic kidney disease, compared to those with essential hypertension, and early diagnosis makes PA a treatable disease. In clinical practice, accurate measurement of plasma aldosterone concentration (PAC) is crucial because entire diagnostic tests critically depend on aldosterone concentrations. Recently, we developed a new chemiluminescent enzyme immunoassay (CLEIA) using a two step sandwich method to measure aldosterone concentrations. We measured PAC in blood samples from patients using a radioimmunoassay (RIA) and the CLEIA (with current and newly improved reagents) as well as liquid chromatography tandem mass spectrometry (LC MS/MS). Based on the results of the Passing Bablok regression analysis, the aldosterone levels measured using CLEIA with the new reagents and those measured by LC MS/MS were found to be significantly correlated. However, aldosterone levels were lower with the improved CLEIA method than with RIA and CLEIA using the current reagent. Since April 2021, the plasma aldosterone concentration has been measured by CLEIA in Japan. As a provisional response due to changes of the measurement method, the Japan Endocrine Society Clinical Practice Guideline for the Diagnosis and Management of Primary Aldosteronism 2021 was announced. This time, we will report on the new measuring method.