Renin Activity
Label Mnemonic: REN
Epic Lab Code: LAB532
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Plasma
Specimen Instructions:
Patient Prep: Collect midmorning after patient has been sitting, standing, or walking for at least 2 hours and seated for 5-15 minutes. Normal sodium diet (100-200 mEq/day) for at least three days. Receiving no medications known to affect renin-aldosterone system.

Supine: Specimen should be obtained between 8 a.m. and 10 a.m. (after at least two hours in supine position).
OR
Upright: Specimen should be obtained before noon (after at least two hours in upright position; seated or standing).

Contact Medical Director if more information is needed.
Collection Medium:
Pink top tube 6 mL (K2-EDTA)
Minimum:
Collect (From either a supine or upright patient) ONE full 6 mL Pink top (EDTA) tube
Preferred Minimum: 2.0 mL
Absolute Minimum: 1.2 mL
Testing requires a dedicated collection tube.
Rejection Criteria:
Serum. Specimens collected in citrate, heparin, or oxalate. Hemolyzed specimens.
Delivery Instructions:
Deliver to laboratory immediately after collection. Critical frozen.
Turn Around Time:
1-3 days upon receipt at reference laboratory
Reference Range:
Adult, normal sodium diet: Supine: 0.2-1.6 ng/mL/hr Upright: 0.5-4.0 ng/mL/hr Children, normal sodium diet, supine: Newborn (1-7 days): 2.0-35.0 ng/mL/hr Cord blood: 4.0-32.0 ng/mL/hr 1-12 months: 2.4-37.0 ng/mL/hr 13 months-3 years: 1.7-11.2 ng/mL/hr 4-5 years: 1.0-6.5 ng/mL/hr 6-10 years: 0.5-5.9 ng/mL/hr 11-15 years: 0.5-3.3 ng/mL/hr Children, normal sodium diet, upright: 0-3 years: Not Available 4-5 years: Less than or equal to 15 ng/mL/hr 6-10 years: Less than or equal to 17 ng/mL/hr 11-15 years: Less than or equal to 16 ng/mL/hr
Interpretive Data:
Plasma renin activity measures enzyme ability to convert angiotensinogen to angiotensin I and is limited by the availability of angiotensinogen. Plasma renin activity is not an accurate indicator of enzyme activity when angiotensinogen is decreased.
Test Limitations:
If an upright sample is collected, patient should be upright (seated or standing) for at least two hours. Do not refrigerate. Do not collect in refrigerated tubes.
Methodology:
Quantitative Enzyme-Linked Immunosorbent Assay
CPT Code:
84244