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Test Category: Specialist Biochemistry

Investigation Name:7α-hydroxy-4-cholesten-3-one

Alias or Abbreviation:7aC4

Intro:

7α-hydroxy-4-cholesten-3-one (7aC4) is a biomarker used in the investigation of Bile Acid Diarrhoea (BAD).

Although BAD affects between 1% and 5% of the population, many individuals remain undiagnosed due to the limited availability of routine diagnostic tests. According to the British Society of Gastroenterology (BSG) 2023 guidelines for investigating chronic diarrhoea, diagnosis can be made using either 75SeHCAT testing or 7aC4 measurement.

75SeHCAT testing has several limitations, including restricted access to scanning facilities, supply chain issues with SeHCAT capsules, high costs, the need for multiple hospital visits, and exposure to radiation.

In contrast, 7aC4 is a bile acid precursor that becomes elevated in cases of bile acid malabsorption and can be measured with a single blood test, making it a more accessible option.

To ensure accurate results, blood samples should be taken while fasting, ideally between 8:00 and 10:00 AM, due to the influence of circadian rhythms. Additionally, factors such as statin use, alcohol consumption, and high triglyceride levels may also affect 7aC4 levels.

Pathology Laboratory:Mass Spec Laboratory

Requestable Seperately?Yes

Minimum Sample Volume:Preferred: 600 µL serum
Absolute minimum: 300 µL

Expected Turnaround Time:14 days

Test Code:7AC4

Sample Type:

Serum

Complex Reference Range:<50 nmol/L: Bile Acid Diarrhoea unlikely. Consider other causes of chronic diarrhoea
50-131 nmol/L: Result in indeterminate range. Consider further investigations, such as SeHCAT
>131 nmol/L: Bile Acid Diarrhoea likely. Consider trial of bile acid sequestrants

Collection Conditions / Other Information:Separate within 12 hours of collection
Store at -20oC and send frozen

Referred to Another Laboratory?No

Storage Requirements:-20oC

Posting Address / Requirements:Send frozen

Sandwell Health Campus
Specialist Chemistry,
Pathology Department,
Lyndon,
B71 4HJ

NPEX / PDF Reporting Available:Yes

Lead Contact Details:Helen Duce, Principal Clinical Scientist
Email: h.duce@nhs.net

Email Address For Chasing Results:rwh-tr.bcpsspecialistchemistryenquiries@nhs.net

Methodology:Liquid chromatography-tandem mass spectrometry

Site Sample Tested:Sandwell Health Campus

Cost:Please email: bcpspathology.info@nhs.net for further details