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Test ID: ACTH Adrenocorticotropic Hormone, Plasma

Reporting Name

Adrenocorticotropic Hormone, P

Useful For

Determining the cause of hypercortisolism and hypocortisolism

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

Interpretation

In a patient with hypocortisolism, an elevated adrenocorticotropic hormone (ACTH) indicates primary adrenal insufficiency, whereas a value that is not elevated is consistent with secondary adrenal insufficiency from a pituitary or hypothalamic cause.

 

In a patient with hypercortisolism (Cushing syndrome), a suppressed value is consistent with a cortisol-producing adrenal adenoma or carcinoma, primary adrenal micronodular hyperplasia, or exogenous corticosteroid use.

 

Normal or elevated ACTH in a patient with Cushing syndrome puts the patient in the ACTH-dependent Cushing syndrome category. This is due to either an ACTH-producing pituitary adenoma or ectopic production of ACTH (bronchial carcinoid, small cell lung cancer, others). Further diagnostic studies such as dexamethasone suppression testing, corticotropin-releasing hormone stimulation testing, petrosal sinus sampling, and imaging studies are usually necessary to define the ACTH source.

 

ACTH concentrations vary considerably depending on physiological conditions. Therefore, ACTH results should always be evaluated with simultaneously measured cortisol concentrations.

Report Available

1 to 3 days

Day(s) Performed

Monday through Friday

Clinical Reference

1. Demers LM: In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 2006; pp 2014-2027

2. Petersen KE: ACTH in normal children and children with pituitary and adrenal diseases I. Measurement in plasma by radioimmunoassay-basal values. Acta Paediatr Scan 1981;70:341-345

Method Name

Electrochemiluminescence Immunoassay

Specimen Type

Plasma EDTA


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.


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma EDTA Frozen (preferred) 28 days
  Refrigerated  3 hours
  Ambient  2 hours

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

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

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ACTH Adrenocorticotropic Hormone, P 2141-0

 

Result ID Test Result Name Result LOINC Value
ACTH Adrenocorticotropic Hormone, P 2141-0

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Oncology Test Request (T729)

Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

mml-adrenal-gonad-pituitary