Pathology Handbook

Renin Recumbent

Patient should be in a recumbent position for 30 minutes prior to, and during the collection.

Endocrine consultation is required in planning renal vein sampling.

If specimens are collected from a location external to Alfred Pathology, they should be spun and the plasma frozen at -80 C. Please note that freezing at -20 C is NOT sufficient and may cause cryo-activation of pro-renin leading to falsely high results.

Once frozen at -80 C, samples can be transferred to, or transported at, -20 C.

Reference Interval:  2.8 - 39.9 mIU/L

Source: Diasorin Liaison kit insert, 200/007-906,06-2016-04

ARR- aldosterone renin ratio

Aldosterone-Renin Ratio (ARR) is a screening test not a diagnostic test for primary hyperaldosteronism. As of 08/06/2017 Aldosterone and Renin are being performed on the Diasorin Liaison XL platform. Please note changed reference intervals.

An aldosterone-renin ratio cut-off of > 70 should prompt further investigation for primary hyperaldosteronism in the appropriate clinical setting. Lower cut-offs improve sensitivity with a loss in specificity whereas higher cut-offs are more specific for primary hyperaldosteronism (with a concomitant loss in sensitivity).

Reference: The Endocrine Society clinical practice guideline on primary hyperaldosteronism,  Funder JW, Carey RM, Mantero F, et al. J Clin Endocrinol Metab 101:1889-1916, 2016

Note: Renin is measured as direct renin mass (mIU/L) rather than plasma renin activity (µg/L/hr) previously. There is no conversion factor for the two assays. Compared to plasma renin activity, renin mass is reduced in high estrogen states (oral contraceptive pill) and increased in patients taking renin inhibitors.