Chemical Pathology

Notes

  • ACTH (adrenocorticotropic hormone) is secreted by the anterior pituitary in response to corticotrophin-releasing hormone from the hypothalamus as well as in response to stress.
  • ACTH stimulates secretion of steroids including Cortisol from the adrenal cortex. This peptide hormone undergoes diurnal variation and samples are usually collected early morning.
  • ACTH is used in the investigation of Cushing's syndrome, and in differentiating primary from secondary causes of adrenal insufficiency.
  • An isolated ACTH level is rarely diagnostically useful as levels should be interpreted in the context of the current cortisol concentration so samples for ACTH must normally be sent with a serum sample for cortisol collected at the same time.

Sample requirements

For adults, blood taken into a 4mL EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

EDTA with cap







For children, blood taken into a 2mL EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

2ml EDTA tube





For neonates, blood taken into an 1.0mL minicollect EDTA tube sent immediately to the laboratory on ICE with a simultaneous tube for cortisol.

Sample tube: pink cap






Storage/transport

Do not store as very unstable. Samples must be sent immediately to the laboratory on ICE. Please contact the laboratory before taking any samples so that requests can be dealt with promptly.

Required information

Relevant clinical details including current medication. Samples and request forms must be labelled with time of collection as well as sample date.

Turnaround times

The samples are sent for analysis once a week to King's College Hospital, London. Results are expected back within 3 weeks.

If required more quickly for clinical reasons, please contact the duty biochemist to discuss.

Reference ranges

For samples collected at 09:00h, the current quoted reference range is 0-50 ng/L, however results must be interpreted in the context of the current cortisol levels, the time of sample collection and the clinical status of the patient.

Further information

To learn more about ACTH visit Lab Tests Online


Page last updated: 20/04/2021

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