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HelpTest Code PRA Renin Activity, Plasma
Reporting Name
Renin Activity, PUseful For
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 syndrome)
This test is not useful for determination of plasma renin concentration.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Plasma EDTASpecimen Required
Patient Preparation: For 4 to 6 weeks before specimen collection, spironolactone (Aldactone) should be discontinued, as plasma renin activity cannot be interpreted if the patient is being treated with spironolactone.
Collection Container/Tube: Chilled, lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.8 mL
Collection Instructions:
1. Draw blood in a chilled syringe from a patient in a seated position; place specimen in a chilled, 3-mL lavender-top (EDTA) tube and mix well. Alternatively, draw blood directly in a chilled, EDTA tube.
2. Immediately place EDTA tube into an ice-water bath until thoroughly cooled.
3. Immediately centrifuge using a refrigerated centrifuge and aliquot plasma into a plastic vial.
Note: If a refrigerated centrifuge is unavailable, chill the centrifuge carriers before use. Centrifuge specimen for 5 minutes or less, then promptly aliquot plasma into a plastic vial.
4. Immediately freeze plasma.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma EDTA | Frozen | 14 days |
Special Instructions
Day(s) Performed
Monday through Friday, Sunday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84244
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PRA | Renin Activity, P | 2915-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8060 | Renin Activity, P | 2915-7 |
Clinical Information
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.
Cautions
Angiotensin-converting enzyme (ACE) inhibitors have the potential to falsely elevate plasma renin activity (PRA). Therefore, in a patient treated with an ACE inhibitor, the findings of a detectable PRA level or a low serum aldosterone/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.
Report Available
2 to 5 daysSpecimen Retention Time
14 daysReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Cardiovascular Test Request (T724)