RENIN ACTIVITY, PLASMA

test app

TEST NAME: RENIN ACTIVITY, PLASMA

LAB DEPT: Core Lab Sendouts

SPECIMEN REQUIREMENTS

Specimen Type:	Blood
Container/Tube
Preferred:	Collect into a CHILLED syringe, then place specimen into a CHILLED Lavender-top (EDTA) Vacutainer®. See collection instructions below under special instructions.
Acceptable:	Collect direct into CHILLED Lavender-top (EDTA) Vacutainer®.
Collection Volume:	4.0 mL (minimum 2.0 mL)
Patient Preparation:	If patient is being treated with Spironolactone (Aldactone), it should be discontinued for 4 to 6 weeks before testing
Sample Rejection:	Specimens that are grossly hemolyzed. Specimens that are not chilled. Mislabeled or unlabeled specimens.
Special Instructions:	1.	Collect specimen into a chilled syringe from a patient in a seated position; place specimen in a chilled lavender-top (EDTA) Vacutainer® and gently invert tube 8-10 times to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting). NOTE: May alternatively collect directly into a chilled, lavender-top vacutainer®.
	2.	Immediately place tube into an ice-water bath until thoroughly cooled.
	3.	Send to lab STAT
	4.	See "Renin-Aldosterone Studies Special Instructions" if further information needed.
	5.	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 reference laboratory will be held and assayed after the radioactivity has sufficiently decayed. This will result in a test delay.

LOGISTICS

Test Availability:	Daily
Turnaround Time:	3-6 days
Test set-up:	Monday-Friday
Lab Testing Section:	Send-outs
Referred to:	Mayo Medical Laboratories (MMLI) / Test ID: PRA

INTERPRETIVE

Reference Range:	0-2 years: 4.6 ng/mL/hour (mean)* Range 1.4-7.8 ng/mL/hr 3-5 years: 2.5 ng/mL/hour (mean)* Range 1.5-3.5 ng/mL/hr 6-8 years: 1.4 ng/mL/hour (mean)* Range 0.8-2.0 ng/mL/hr 9-11 years: 1.9 ng/mL/hour (mean)* Range 0.9-2.9 ng/mL/hr 12-17 years: 1.8 ng/mL/hour (mean)* Range 1.2-2.4 ng/mL/hr 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) Range: 2.9-24.0 ng/mL/hour > or =40 years: 5.9 ng/mL/hour (mean) Range: 2.9-10.8 ng/mL/hour Na-replete, upright (peripheral vein specimen) 18-39 years: 1.9 ng/mL/hour (mean) Range: < or =0.6-4.3 ng/mL/hour > or =40 years: 1.0 ng/mL/hour (mean) Range: < or =0.6-3.0 ng/mL/hour *Stalker HP, Holland NH, Kotchen JM, Kotchen TA: Plasma renin activity in healthy children. J Pediatr 1976;89:256-258
Critical Values:	None established
Limitations:	The plasma renin activity cannot be interpreted if the patient is being treated with spironolactone (Aldactone).. 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.
Methodology:	Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Test Classification:	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.

ADDITIONAL INFORMATION

For SLCH Laboratory use only

Lab Processing instructions:	Keep specimen on wet ice until able to process. Centrifuge specimen (for < or =5 minutes) in a refrigerated centrifuge and immediately transfer plasma to 5-mL screw-capped plastic vial. Place aliquot in dry ice to freeze immediately, (If a refrigerated centrifuge is unavailable, chill the centrifuge carriers.)
Processed Volume:	2.0 mL (minimum 1.2 mL) EDTA plasma
Transport Temperature:	Frozen
Analyte Stability (Plasma):	PROCESSED Ambient: NA Refrigerated: NA Frozen: 14 days
Notes:	Reject if specimen received is room temperature (un-chilled) Reject due to gross hemolysis (mild okay) DO NOT freeze/thaw

GENERAL INFORMATION

EPIC order name:	Renin Activity (EPIC Test# LAB5362)
Cerner order name:	Renin Act Plas
CPT Codes:	84244
LOINC Value:	2915-7
Synonyms:	PRA
Last Updated: 08/18
Last Reviewed: 12/23