Lab Test

Corticosterone, 18-OH-

Hydroxycorticosterone, 18-

Test Codes

LabCorp #500778, Esoterix #500088, EPIC: LAB6062, SOFT: X18OH

Instructions

A number of drugs are known to influence endocrine function directly, or to interfere with assay methodology. Whenever possible, physicians should consider discontinuing all drugs, except those necessary to the patient's well-being, several days prior to sample collection. Always note any drugs being administered on the Test Request Form.

Specimen Collection Criteria

Collect (preferred specimen): Two Gold-top SST tubes.
Also acceptable: Two plain Red-top tubes.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within one hour of collection. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below).

Preparation for Courier Transport

Transport: 3.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 1.0 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within one hour of collection. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below).

Transport: 3.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 1.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 24 hours
Frozen (-20°C/-4°F or below): 90 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Sendout Laboratory with any questions.

Laboratory

Sent to LabCorp Esoterix Endocrinology, Calabassas Hills, CA.

Performed

Monday.
Results available in 4-10 days.

Reference Range

By report.

Test Methodology

High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS).

Interpretation

By report.

Clinical Utility

18-hydroxycorticosterone is the immediate precursor to aldosterone. Concentrations of 18-hydroxycorticosterone are more elevated in primary aldosteronism than in hyperplasia; this is usually demonstrated in an early morning specimen taken after the patient has laid down overnight.

CPT Codes

82542

Contacts

Last Updated

8/25/2022

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