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HelpTest Code ACTH Adrenocorticotropic Hormone, Plasma
Reporting Name
Adrenocorticotropic Hormone, PUseful For
Determining the cause of hypercortisolism and hypocortisolism
Specimen Type
Plasma EDTANecessary Information
Separate specimens should be submitted when multiple tests are ordered.
Specimen Required
Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube: Ice-cooled, lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Morning (7 a.m.-10 a.m.) specimen is desirable.
2. Collect with a pre-chilled lavender top (EDTA) tube and transport to the laboratory on ice.
3. Within 2 hours of collection centrifuge at refrigerated temperature 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)
Reference ranges are based on samples drawn between 7 a.m.-10 a.m.
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(3):341-345
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
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
Corticotropin (previously 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 nadir (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 corticotropin (previously 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.
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
Method Name
Electrochemiluminescence Immunoassay
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Oncology Test Request (T729)