Renin Activity, Plasma
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Investigation of primary aldosteronism (eg, adrenal adenoma/carcinoma and adrenal cortical hyperplasia) and secondary aldosteronism (renovascular disease, salt depletion, potassium loading, cardiac failure with ascites, pregnancy, Bartter's syndrome)
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Renin Activity, P
PRA (Plasma Renin Activity)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Collection Container/Tube: Chilled, lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
1. Draw blood in a chilled syringe from a patient in a seated position; place specimen in a chilled, lavender top (EDTA) tube; and mix.
2. Alternatively, draw blood directly in a chilled, lavender top (EDTA) tube.
3. Immediately place EDTA tube into an ice-water bath until thoroughly cooled.
4. Refrigerate specimen during centrifugation and immediately transfer plasma to plastic vial. (If a refrigerated centrifuge is unavailable, chill the centrifuge carriers. Centrifuge specimen for < or =5 minutes, then promptly transfer plasma.)
Additional Information: See Renin-Aldosterone Studies in Special Instructions for further information.
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Mild OK; Gross OK
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Plasma EDTA||Frozen||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The renal juxtaglomerular apparatus generates renin, an enzyme that converts angiotensinogen to angiotensin I. The inactive angiotensin I is enzymatically converted to the active octapeptide angiotensin II, a potent vasopressor responsible for hypertension of renal origin. Angiotensin II also stimulates the zona glomerulosa of the adrenal cortex to release aldosterone.
Renin secretion by the kidney is stimulated by a fall in glomerular blood pressure, by decreased sodium concentration at the macula densa at the distal tubule, or by stimulation of sympathetic outflow to the kidney, such as in renal vascular diseases.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
0-2 years: 4.6 ng/mL/hour (mean)*
3-5 years: 2.5 ng/mL/hour (mean)*
6-8 years: 1.4 ng/mL/hour (mean)*
9-11 years: 1.9 ng/mL/hour (mean)*
12-17 years: 1.8 ng/mL/hour (mean)*
Mean data not standardized as to time of day or diet. Infants were supine, children sitting.
Na-depleted, upright (peripheral vein specimen)
18-39 years: 10.8 ng/mL/hour (mean)
2.9-24.0 ng/mL/hour (range)
> or =40 years: 5.9 ng/mL/hour (mean)
2.9-10.8 ng/mL/hour (range)
Na-replete, upright (peripheral vein specimen)
18-39 years: 1.9 ng/mL/hour (mean)
< or =0.6-4.3 ng/mL/hour (range)
> or =40 years: 1.0 ng/mL/hour (mean)
< or =0.6-3.0 ng/mL/hour (range)
*Stalker HP, Holland NH, Kotchen JM, Kotchen TA: Plasma renin activity in healthy children. J Pediatr 1976;89:256-258
A high ratio of serum aldosterone (SA) in ng/dL to plasma renin activity (PRA) in ng/mL per hour, is a positive screening test result, a finding that warrants further testing. A SA/PRA ratio > or =20 and SA > or =15 ng/dL indicates probable primary aldosteronism.
Renal disease, such as unilateral renal artery stenosis, results in elevated renin and aldosterone levels. Renal venous catheterization may be helpful. A positive test is a renal venous renin ratio (affected/normal) >1.5.
See Renin-Aldosterone Studies in Special Instructions.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The plasma renin activity cannot be interpreted if the patient is being treated with spironolactone (Aldactone). Spironolactone (Aldactone) should be discontinued for 4 to 6 weeks before testing.
Angiotensin converting enzyme (ACE) inhibitors have the potential to "falsely elevate" PRA. Therefore, in a patient treated with an ACE-inhibitor, the findings of a detectable PRA level or a low SA/PRA ratio do not exclude the diagnosis of primary aldosteronism. In addition, a strong predictor for primary aldosteronism is a PRA level undetectably low in a patient taking an ACE-inhibitor.
Not useful for determination of plasma renin concentration.
This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. A recommended time period before collection cannot be made because it will depend on the isotope administered, the dose given and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held and assayed after the radioactivity has sufficiently decayed. This will result in a test delay.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Young WF Jr: Primary aldosteronism: A common and curable form of hypertension. Cardiol Rev 1999;7:207-214
2. Young WF Jr: Pheochromocytoma and primary aldosteronism: diagnostic approaches. Endocrinol Metab Clin North Am 1997;26:801-827
Method Description Describes how the test is performed and provides a method-specific reference
The renin in plasma is allowed to act on the plasma's endogenous substrate, angiotensinogen, producing angiotensin I. This is measured by radioimmunoassay. Renin activity is expressed in ng of angiotensin produced per mL of plasma per hour of incubation.(Haber E, Koerner T, Page LB, et al: Application of a radioimmunoassay for angiotensin I to the physiologic measurements of plasma renin activity in normal human subjects. J Clin Endocrinol Metab 1969;29:1349-1355)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 1 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|8060||Renin Activity, P||2915-7|