Renin

Diagnostic Use

PLEASE NOTE - there are updated pre-analytical handling conditions for renin samples. Please read the specimen collection and transport to CHL information below.

Aetiology of hypertension (primary hyperaldosteronism and other mineralocorticoid excess states associated with high blood pressure, renal artery stenosis, renin secreting tumours). Best done in conjunction with measurement of plasma aldosterone (there are different specimen handling and transport requirements, see aldosterone test guide).

Localising renal ischaemic disease (renal vein renin sampling).

Diagnosis of primary adrenocortical insufficiency and assessing adequacy of mineralocorticoid replacement.

Diagnosis of Bartter syndrome.

Diagnosis of hypovolaemic disorders (e.g. patients presenting with hyponatraemia, postural hypotension etc).

Diagnosis of hyporeninaemic syndromes.

Department

Endocrinology Lab

Delphic Registration Code

REND

Laboratory Handling

Phlebotomy

Please take separate EDTA for renin

Registration

Please check renin has assigned to its own EDTA tube and is NOT shared with CBC or HbA1c.

Separating

Samples should be separated within 6 hours of collection - do NOT store samples refrigerated or at -20C. Plasma renin is stable for up to 5 days if stored ambient.

Laboratory

Samples should be separated within 6 hours of collection - do NOT store samples refrigerated or at -20C. Plasma renin is stable for up to 5 days if stored ambient.

Test Adds

Not available.

Synonyms

ARR
Aldo-renin ratio

Turnaround Time

7 days

Test Code

8373

Specimen Type

• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred if West Coast

• EDTA (Lavender Cap)

Acceptable

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.5

Minimum Sample Volume (ml)

1.0

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.5

Minimum Sample Volume (ml)

1.0

Pre-testing Requirements

Patient's posture, salt intake, drug therapy, age and time of sampling affect levels. Potassium depletion and/or hypokalaemia lower renin - aldosterone secretion.
Outpatients are best screened as follows: If possible, stop non-essential anti-hypertensives for 2 weeks before sampling. Many hypotensive drugs alter renin - aldosterone levels; preferred agents are Alpha-blockers (Doxazosin, Prazosin) and non-dihydropyridine calcium channel blockers (Verapamil, Diltiazem) since they do not greatly alter renin - aldosterone. Screening tests for primary hyperaldosteronism and related conditions can still be done in patients on betablockers, ACE inhibitors and/or diuretics, BUT interpretation must allow for the potent effects these drugs have on the renin - aldosterone axis. Patients should attend (non-fasting) prior to 10.00 am for "ambulant sampling of plasma aldosterone and renin. It is usually wise to check plasma Na, K and creatinine at the time of sampling.

Additional Specimen Information

Inpatients are screened as above and should be ambulated for at least 30 minutes before sampling.

Other protocols involving plasma aldosterone/renin measurement include saline suppression (2L saline administration over 4 hours), 4-hour posture test (08.00 overnight supine aldosterone, repeated after 4 hr of upright posture) and tests using ACTH stimulation or dexamethasone suppression.

If patient is on high dose biotin therapy (>5 mg/day), wait until at least 8 hours after last dose to take blood sample.

If Renin or Aldosterone-Renin ratio is required, preferably collect blood before 10 am.

Aliquot Instructions

Sample Type

• Plasma

Minimum Volume (ml)

1

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Do NOT refrigerate or freeze samples at -20C as this can cause cryoactivation of prorenin and falsely elevated results.

Separate renin samples within 6 hours of collection and store plasma ambient.
Transport separated plasma to CHL ambient. Samples arriving chilled or frozen will be rejected.
Plasma renin is stable at ambient temperature for up to 5 days.

Renin requires a dedicated aliquot - sample is NOT able to be shared with other departments.

West Coast/Referral labs: Collection sites without the ability to separate and send the sample to CHL ambient within 5 days need to consider sending the patient to a main centre for collection to ensure sample is appropriately stored and transported for testing.

Reference Intervals

07.00 – 10.00 Ambulant (adult): 5.3 – 99.1 mIU/L

07.00 – 10.00 Supine (adult): 4.2 – 59.7 mIU/L

Test Method

Chemiluminescence

Non-Funded Test Cost

$47.36 (Exclusive of GST)

Billing Code

8373

Contact Information

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