Medición de la concentración plasmática de renina inmunoreactiva por un método automatizado y su correlación con la actividad de renina plasmática Measurement of Immunoreactive Plasma Renin Concentration by an Automated Method and its Correlation with Plasma Renin Activity

It is under discussion whether the results of immunoreactive renin concentration (RC) provide the same information as plasma renin activity (PRA). Additionally, it has been suggested that the determination of the aldosteronemia / PRA ratio (ARR) has a higher positive predictive value than isolated determinations of PRA and aldosterone (A) for screening of primary hyperaldosteronism (PHA). We designed an experimental and prospective study of 227 consecutive samples from ambulatory individuals, none of them with a definitive diagnosis of PHA. Our objective was to evaluate: 1) the correlation of results from an automated method to measure RC (LIAISON, DiaSorin) with respect to the PRA. (RIA, DiaSorin). 2) the presumptive diagnosis concordance (PDC) between the results of RC and PRA. 3) the correlation between the results of of the A/ CR ratio (ACR) and ARR. Results: There is a high significant correlation (p < 0.0001) between results of PRA and RC, with a PDC = 83 % for regular and high PRA. However, PDC is low and not acceptable for low levels of PRA (< 1.3 ng/mL/hr). The correlation between the results of A/RC ratio (ACR) and ARR is highly significant (p < 0.0001). Conclusions: RC methodology would be useful for an initial study of a patient, in