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Test Code ACTH Adrenocorticotropic Hormone (ACTH), Plasma

Reporting Name

Adrenocorticotropic Hormone, P

Useful For

Determining the cause of hypercortisolism and hypocortisolism

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Plasma EDTA


Specimen Required


Patient Preparation: For 12 hours before this test do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Supplies: Aliquot Tube, 5 mL (T465)

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 EDTA tube and transport to the laboratory on ice.

3. Spin down in a refrigerated centrifuge within 2 hours and immediately separate plasma from cells.

4. Immediately freeze plasma.

Additional Information: Separate specimens should be submitted when multiple tests are ordered.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
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

Day(s) and Time(s) Performed

Monday through Friday; 5 a.m.-12 a.m., Saturday; 6 a.m.-6 p.m.

Test Classification

This test has been cleared or approved by the U.S. 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

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 nadirs (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.

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.

 

Samples should not be taken from patients receiving therapy with high biotin or vitamin B7 doses (ie, >5 mg/day) until at least 12 hours following the last biotin administration.

 

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.

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 Description

Testing is performed on the Roche Cobas e601. The Roche adrenocorticotropic hormone (ACTH) assay is a sandwich, electrochemiluminescence immunoassay that employs a biotinylated monoclonal ACTH-specific antibody and a monoclonal ACTH specific antibody labeled with a ruthenium complex. ACTH in the specimen reacts with both the biotinylated monoclonal ACTH-specific antibody and the monoclonal ACTH-specific antibody labeled with a ruthenium complex, forming a sandwich complex. Streptavidin-coated microparticles are added and the mixture incubates allowing the newly formed sandwich complex to become bound to the solid phase via the biotin streptavidin interaction. The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Application of voltage to the electrode induces the chemiluminescent emission, which is then measured.

 

The assay employs two monoclonal antibodies specific for ACTH (9-12) and for the C-terminal region (ACTH 36-39). Due to common antigenic structure, the antibodies recognize intact biologically active ACTH 1-39 and the ACTH precursors pro-opiomelanocortin (POMC) and pro-ACTH.(Package insert: ACTH, Roche Diagnostics, V 9.0, 2016-10)

Analytic Time

Same day/1 day

Specimen Retention Time

14 days

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross OK

Icterus

NA

Other

NA

 

NY State Approved

Yes

Method Name

Electrochemiluminescence Immunoassay

Forms

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

-General Request (T239) (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf)

-Oncology Test Request Form (T729) (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)