Bile Salts (for obstetric cholestasis), Serum

Diagnostic Use

Bile salts (also known as bile acids) are cholesterol metabolites that play a role in the dietary absorption of fats.

In cholestasis (impaired bile flow), bile acids backflow into the plasma, resulting in an elevation of the plasma bile acid concentration. Measurement of bile acids is useful in the diagnosis of obstetric cholestasis, a complication of pregnancy.

Department

Core Biochemistry

Delphic Registration Code

BILE

Synonyms

Bile Acids (for obstetric cholestasis)

Turnaround Time

3 hours

Test Code

4774

Specimen Type

• Serum
• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Acceptable

• Serum (Red Cap)
• SST II (Gold Cap)
• Lithium Heparin - Gel (Green Cap)

Preferred Sample Volume (ml)

4.5

No of Samples Required

1

Pre-testing Requirements

A fasting sample should be collected.

Aliquot Instructions

Transport to Lab

Frozen
If overnight - Frozen

Interpretation

A fasting specimen is preferred.

The finding of elevated bile acids in a pregnant patient is suggestive of obstetric cholestasis (OC), particularly if the LFTs are otherwise largely unremarkable and the patient has symptoms of OC (e.g. itching).  This is a non-specific finding however, as bile acids may also be elevated in other liver disorders.

Gross elevations of plasma bile acids may be associated with adverse foetal outcomes although the data on this relationship is unclear.  Bile acids results may be contribute towards management decisions in pregnancy, but it is not recommended that decisions are made from the bile acid result alone.

OC is often treated with ursodeoxycholic acid (UDCA) which is itself a bile acid.  Monitoring of serum bile acids in a patient on UDCA may present a challenge as the assay will recognise the UDCA which can lead to spuriously high results.  If the patient is on UDCA, it is best to collect a trough (pre-dose) fasting bile acids level to minimise the impact of the drug on the result.

Reference Intervals

Fasting reference interval: <15 umol/L

Test Method

Performed on Beckman Coulter AU5822 analyser using Sentinel Reagents.

Non-Funded Test Cost

$93.83 (Exclusive of GST)

Billing Code

4774

Contact Information

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