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Test Code LAB0213504 Renin Activity, Plasma

Additional Codes

Mayo Test ID
PRA

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful 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.

Special Instructions

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Portions of this test are covered by patents held by Quest Diagnostics

Reporting Name

Renin Activity, P

Specimen Type

Plasma EDTA


Specimen 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.


CentraCare Laboratory Services Note:

Freeze plasma within 1 hour of collection and submit frozen.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma EDTA Frozen 14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Reference Values

0-2 years: 4.6 ng/mL/h (mean)* Range: 1.4-7.8 ng/mL/h

3-5 years: 2.5 ng/mL/h (mean)* Range: 1.5-3.5 ng/mL/h

6-8 years: 1.4 ng/mL/h (mean)* Range: 0.8-2.0 ng/mL/h

9-11 years: 1.9 ng/mL/h (mean)* Range: 0.9-2.9 ng/mL/h

12-17 years: 1.8 ng/mL/h (mean)* Range: 1.2-2.4 ng/mL/h

Mean data not standardized as to time of day or diet. Infants were supine, children sitting.

*Stalker HP, Holland NH, Kotchen JM, Kotchen TA. Plasma renin activity in healthy children. J Pediatr. 1976;89(2):256-258

 

Na-depleted, upright (peripheral vein specimen)

18-39 years: 10.8 ng/mL/h (mean)

2.9-24.0 ng/mL/h (range)

≥40 years: 5.9 ng/mL/h (mean)

2.9-10.8 ng/mL/h (range)

 

Na-replete, upright (peripheral vein specimen)

18-39 years: 1.9 ng/mL/h (mean)

≤0.6-4.3 ng/mL/hour (range)

≥40 years: 1.0 ng/mL/h (mean)

≤0.6-3.0 ng/mL/h (range)

Interpretation

A high ratio of serum aldosterone (SA) in ng/dL to plasma renin activity (PRA) in ng/mL/h, is a positive screening test result, a finding that warrants further testing. A SA:PRA ratio greater than or equal to 20 and SA of greater than or equal to 15 ng/dL indicates probable primary aldosteronism.

 

Kidney disease, such as unilateral renal artery stenosis, results in elevated renin and aldosterone levels. Kidney venous catheterization may be helpful. A positive test is a renal venous renin ratio (affected:normal) above 1.5.

 

For more information see Renin-Aldosterone Studies.

Day(s) Performed

Monday through Friday, Sunday

Report Available

2 to 5 days

Specimen Retention Time

14 days

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

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Cardiovascular Test Request (T724)