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HelpMayo Test ID BAFS Bile Acids, Fractionated and Total, Serum
Ordering Guidance
This test is useful in diagnosing intrahepatic cholestasis of pregnancy and does not support the assessment of either peroxisomal biogenesis disorders or inborn errors of bile acid metabolism.
For diagnostic testing for peroxisomal biogenesis disorders, order BAIPD / Bile Acids for Peroxisomal Disorders, Serum.
Specimen Required
Patient Preparation: Patient must be fasting for 12 to 14 hours.
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Useful For
Measuring tauro- and glycol-conjugated and unconjugated bile acid constituents in serum specimens
Monitoring patients receiving bile acid therapy, such as cholic acid, deoxycholic acid, or ursodeoxycholic acid
Aiding in the evaluation of liver function; evaluation of liver function changes before the formation of more advanced clinical signs of illness such as icterus
Determining hepatic dysfunction as a result of chemical and environmental injury
Indicating hepatic histological improvement in chronic hepatitis C patients responding to interferon treatment
Indicating intrahepatic cholestasis of pregnancy
This assay is not useful for the diagnosis of peroxisomal biogenesis disorders or inborn errors of bile acid metabolism.
Testing Algorithm
For more information see Bile Acid-Associated Tests Ordering Guide
Special Instructions
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Bile Acids, Fractionated and Tot, SSpecimen Type
SerumSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 90 days | |
| Ambient | 90 days | ||
| Frozen | 90 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
Clinical Information
Bile acids are formed in the liver from cholesterol, conjugated primarily to glycine and taurine, stored and concentrated in the gallbladder, and secreted into the intestine after the ingestion of a meal. In the intestinal lumen, the bile acids serve to emulsify ingested fats and thereby promote digestion. During the absorptive phase of digestion, approximately 90% of the bile acids are reabsorbed.
The efficiency of the hepatic clearance of bile acids from portal blood maintains serum concentrations at low levels in normal persons. An elevated fasting level, due to impaired hepatic clearance, is a sensitive indicator of liver disease. Following meals, serum bile acid levels have been shown to increase only slightly in normal persons but markedly in patients with various liver diseases, including cirrhosis, hepatitis, cholestasis, portal-vein thrombosis, Budd-Chiari syndrome, cholangitis, Wilson disease, and hemochromatosis. No increase in bile acids will be noted in patients with intestinal malabsorption. Metabolic hepatic disorders involving organic anions (eg, Gilbert disease, Crigler-Najjar syndrome, and Dubin-Johnson syndrome) do not cause abnormal serum bile acid concentrations.
Reference Values
Total cholic acid: ≤5.00 nmol/mL
Total chenodeoxycholic acid: ≤6.00 nmol/mL
Total deoxycholic acid: ≤6.00 nmol/mL
Total ursodeoxycholic acid: ≤2.00 nmol/mL
Total bile acids: ≤19.00 nmol/mL
Interpretation
Total bile acids are metabolized in the liver and can serve as a marker for normal liver function. Increases in serum bile acids are seen in patients with acute hepatitis, chronic hepatitis, liver sclerosis, liver cancer, and intrahepatic cholestasis of pregnancy.
Cautions
This test does not measure sulfated bile acids.
Clinical Reference
1. Marschall HU. Management of intrahepatic cholestasis of pregnancy. Expert Rev Gastroenterol Hepatol. 2015;9(10):1273-1279
2. Ducroq DH, Morton MS, Shadi N, et al. Analysis of serum bile acids by isotope dilution-mass spectrometry to assess the performance of routine total bile acid methods. Ann Clin Biochem. 2010;47(Pt 6):535-540
3. Piechota J, Jelski W. Intrahepatic cholestasis in pregnancy: Review of the literature. J Clin Med. 2020;9(5):1361. doi:10.3390/jcm9051361
4. Society for Maternal-Fetal Medicine (SMFM). Lee RH, Mara Greenberg, Metz TD, Pettker CM. Society for Maternal-Fetal Medicine Consult Series #53: Intrahepatic cholestasis of pregnancy: replaces consult #13, April 2011. Am J Obstet Gynecol. 2021;224(2):B2-B9. doi:10.1016/j.ajog.2020.11.002
Method Description
Bile acid concentrations in serum are measured by liquid chromatography tandem mass spectrometry stable isotope dilution analysis. Serum is mixed with isotopically labeled internal standards of selected bile acids and then subjected to protein precipitation. Sample preparation is semi-automated using a liquid handler. Reverse-phase liquid chromatography is performed using mobile phases to separate free bile acids, their respective tauro- and glyco-conjugates, and 2 bile acid precursors.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
3 to 5 daysSpecimen Retention Time
1 monthPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| BAFS | Bile Acids, Fractionated and Tot, S | 43130-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 35796 | Total Cholic acid | 30518-5 |
| 35797 | Total Chenodeoxycholic acid | 30519-3 |
| 35798 | Total Deoxycholic acid | 30520-1 |
| 35799 | Total Ursodeoxycholic acid | 55159-8 |
| 35800 | Total bile acids | 14628-2 |