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HelpTest ID ACTH Adrenocorticotropic Hormone, Plasma
Necessary Information
Separate specimens should be submitted when multiple tests are ordered.
Specimen Required
Patient Preparation: For the 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube: Ice-cooled, lavender top (EDTA)
Submission Container/Tube: Plastic, 5 mL, aliquot tube
Specimen Volume: 1 mL
Collection Instructions:
1. Morning (6 a.m.-10:30 a.m.) specimen is desirable.
2. Collect with a pre-chilled lavender top (EDTA) tube and transport to the laboratory on ice.
3. Centrifuge at refrigerated temperature within 2 hours and immediately separate plasma from cells.
4. Immediately freeze plasma.
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Oncology Test Request (T729)
Secondary ID
8411Useful For
Determining the cause of hypercortisolism and hypocortisolism
Method Name
Electrochemiluminescence Immunoassay
Reporting Name
Adrenocorticotropic Hormone, PSpecimen Type
Plasma EDTASpecimen Minimum Volume
0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen (preferred) | 28 days |
| Refrigerated | 3 hours | |
| Ambient | 2 hours |
Clinical Information
Adrenocorticotropic hormone (ACTH) is synthesized by the pituitary in response to corticotropin-releasing hormone (CRH), which is released by the hypothalamus. ACTH stimulates adrenal cortisol production. Plasma ACTH and cortisol levels exhibit peaks (6-8 a.m.) and troughs (11 p.m.).
Disorders of cortisol production that might affect circulating ACTH concentrations include:
Hypercortisolism
-Cushing syndrome:
- Cushing disease (pituitary ACTH-producing tumor)
- Ectopic ACTH-producing tumor
- Ectopic CRH
- Adrenal cortisol-producing tumor
- Adrenal hyperplasia (non-ACTH dependent, autonomous cortisol-producing adrenal nodules)
Hypocortisolism
-Addison disease-primary adrenal insufficiency
-Secondary adrenal insufficiency
-Pituitary insufficiency
-Hypothalamic insufficiency
-Congenital adrenal hyperplasia-defects in enzymes involved in cortisol synthesis
Reference Values
7.2-63 pg/mL (a.m. draws)
No established reference values for p.m. draws
Pediatric reference values are the same as adults, as confirmed by peer reviewed literature.
Petersen KE: ACTH in normal children and children with pituitary and adrenal diseases. I. Measurement in plasma by radioimmunoassay-basal values. Acta Paediatr Scand 1981;70:341-345
For SI unit Reference Values, see https://www.mayocliniclabs.com/order-tests/si-unit-conversion.html
Cautions
In very rare instances of the ectopic adrenocorticotropic hormone (ACTH) syndrome, the elevated ACTH may be biologically active but not detected by the immunometric assay.
Falsely elevated values may occur in plasma from patients who have developed human antimouse antibodies or heterophilic antibodies.
In rare cases, interference due to extremely high titers of antibodies to analyte-specific antibodies, streptavidin, or ruthenium can occur.
Under ACTH 1-24 medication, ACTH measurement is not recommended, due to negative interference with the sandwich assay.
Patients taking glucocorticoids may have suppressed levels of ACTH with an apparent high level of cortisol. This may be due to cross-reactivity with the cortisol immunoassays. If exogenous Cushing is suspected, a cortisol level determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (eg, CINP / Cortisol, Serum, LC-MS/MS) should be used with the ACTH level for the interpretation.
Values obtained with different assay methods or kits may be different and cannot be used interchangeably. Test results cannot be interpreted as absolute evidence for the presence or absence of malignant disease.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82024