18-Hydroxycorticosterone

Test Code

94621

CPT Codes
82528

Preferred Specimen

0.5 mL serum collected in a red-top tube (no gel)

Minimum Volume

0.25 mL

Instructions

Collect specimen in a non-additive red-top tube. Spin down immediately and pour off into a 13 x 75 mm plastic tranport tube.

Transport Container

Transport tube

Transport Temperature

Frozen

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Moderate hemolysis • Grossly lipemic • Grossly icteric • Serum separator tube

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

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Mon, Wed; Report available: 9 days

Reference Range

Adult

Males	≤175 ng/dL
Females
Pre-Menopausal Mid Follicular	≤98 ng/dL
Pre-Menopausal Surge	≤152 ng/dL
Pre-Menopausal Mid Luteal	36-164 ng/dL

Pediatric

<30 days	Not established
1-11 months	≤165 ng/dL
1 year	≤140 ng/dL
2 years	≤129 ng/dL
3 years	≤128 ng/dL
4 years	≤133 ng/dL
5 years	≤142 ng/dL
6 years	≤151 ng/dL
7 years	≤160 ng/dL
8 years	≤164 ng/dL
9 years	≤166 ng/dL
10 years	≤165 ng/dL
11 years	≤163 ng/dL
12 years	≤159 ng/dL
13 years	≤155 ng/dL
14 years	≤151 ng/dL
15 years	≤146 ng/dL
16 years	≤142 ng/dL
17 years	≤138 ng/dL

Clinical Significance

Primary aldosteronism should be suspected whenever a patient has the triad of hypertension, hypokalemia, and inappropriate renal potassium wasting. The biggest challenge is the differential diagnosis between the more common adrenal adenoma and bilateral hyperplasia. Because adrenal adenomas increase the circulating levels of 18-hydroxycorticosterone (18-OH B), serum levels of 18-OH B may be useful to differentiate them from bilateral adrenal hyperplasia. The cutoff point appears to be about 50 ng/dL of serum. Most values are around 100 ng/dL. The higher the level of this precursor, the greater the possibility that an adrenal adenoma is present.
J Clin Endocrinol Metab. 97: 881-9, 2012.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.