Comparative analysis of direct renin levels and plasma renin activity for the purpose of monitoring the patients with congenital adrenal cortical hyperplasia

Abstract

The high prevalence of diseases associated with the disturbances in the renin-angiotensin-aldosterone system (RAAS) including those affecting the children dictates the necessity of the development and application of highly specific, accurate, and sensitive indices. One of them widely used at present is plasma renin activity (PRA). Meanwhile, foreign researchers have demonstrated significant correlation between PRA and direct renin concentration that can be determined by a technically simpler and readily available method. We are unaware of the studies with the application of this approach reported in the Russian-language publications. The present work was designed to consider the possibility of using direct rennin levels and PRA for monitoring health conditions of the children presenting with congenital adrenal cortical hyperplasia. PRA and direct rennin concentrations were determined with the use of the relevant assay kits in 72 patients admitted to the Pediatric Department of Endocrinological Research Centre. Group 1 was comprised of 44 patients presenting with congenital adrenal cortical hyperplasia (CAH), group 2 consisted of 28 patients with the presumably unaffected adrenal function. Direct rennin concentrations and PRA are known to have virtually identical diagnostic value, i.e. they can equally well be used to diagnose disorders of RAAS functions including those in the patients with CAH. However, the measurement of direct rennin permits to more precisely detect hyperaldosteronism and identify children exhibiting symptoms of mineralocorticoid overdose. The patients with the supposedly normal functioning adrenal glands were also found to show high percentage of abnormal PRA values and direct rennin levels which suggests the relationship between the functions of RAAS and other endocrine organs.