The measurement of plasma aldosterone concentration (PAC) and renin activity (PRA) or active renin concentration (ARC) is clinically important not only for detection of primary aldosteronism but also for the selection of antihypertensive agents to treat patients successfully. .However, it has taken approximately 7 days for clinicians to get the results. Of late, we developed the novel rapid non-RIA assays of PAC and ARC, which are measurable in 10 minutes. This study is intended to investigate the utility and accuracy of this new methods.Design and Method:
Both PAC and ARC were simultaneously measured by chemiluminescent enzyme immunoassay (CLEIA) system machine with their specific monoclonal antibodies and were automatically washed by the immobilized magnetic particles. We retrospectively compared RIA-assayed PAC, PRA, ARC and LC-MS/MS-measured PAC with CLEIA-measured PAC and ARC in 290 patients with aldosterone producing adenoma (APA, n = 100), bilateral idiopathic hyperaldosteronism (IHA, n = 100) and essential hypertension (EH, n = 90).Results:
CLEIA-measured PAC were significantly correlated with RIA-assayed PAC (y = 0.9846 x + 2.5708, Spearman's r = 0.9072, P < 0.0001), and also significantly correlated with LC-MS/MS PAC (y = 1.039x + 8.0, Spearman's r = 0.997, P < 0.0001). Rapid CLEIA-measured ARC with the lower detection limit of 0.25 pg/mL, which is very small as compared to 2 pg/mL in RIA-assayed ARC, were significantly correlated with RIA-assayed ARC (y = 1.0103 x + 0.9156, Spearman's r = 0.8166, P < 0.0001), and also significantly correlated with RIA-assayed PRA (Spearman's r = 0.8091 y = 4.4331 x + 0.4456, P < 0.0001). ARR-A and ARR-C of APA patients were 206 ± 21.7 and 64.5 ± 5.1 (Mean ± SEM), respectively. ARR-A and ARR-C of IHA patients were 42.8 ± 4.7 and 13.2 ± 0.9, and those of EH patients 15.4 ± 3.1 and 3.0 ± 0.5, respectively.Conclusions:
Our ten minute measurement of PAC and ARC were proved to be very accurate and might be clinically useful.