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Test Code 7AC4 7AC4, Bile Acid Synthesis, Serum


Specimen Required


Patient Preparation:

1. Patient must fast for at least 12 hours prior to collection; fasting morning specimen is preferred.

2. Patient should not be taking bile acid sequestrants for 24 hours prior to collection or statins for 5 days prior to collection.

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge and aliquot 1 mL of serum into plastic vial.

2. Send specimen frozen.


Useful For

Screening for bile acid malabsorption in patients with irritable bowel syndrome with diarrhea

Reporting Name

7AC4, Bile Acid Synthesis, S

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 90 days
  Refrigerated  72 hours
  Ambient  24 hours

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

≥18 years: 2.5-63.2 ng/mL

Reference values have not been established for patients who are <18 years of age.

Supportive Data

In an internal study of 55 patients with irritable bowel syndrome with diarrhea, a fasting serum 7 alpha-hydroxy-4-cholesten-3-one (7aC4) result of 17.6 ng/mL or above was 83% sensitive and 53% specific for identifying patients with elevated fecal bile acids (eg, patient with bile acid diarrhea).(3) In another study, a result above 52.5 ng/mL resulted in 40% sensitivity and 85% specificity for BAD.(4)

Additional internal studies have shown that a combination of serum 7aC4 above 52.5 ng/mL and primary fecal bile acids above 10% is 66% sensitive and 95% specific for BAD.(2)

Day(s) Performed

Monday, Thursday

Report Available

5 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
7AC4 7AC4, Bile Acid Synthesis, S 94866-1

 

Result ID Test Result Name Result LOINC Value
65504 7AC4, Bile Acid Synthesis, S 94866-1

Forms

If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen

Testing Algorithm

For more information see Ordering Guide: Bile Acid-Associated Tests.