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Test Code FBAC Bile Acids, Urine


Specimen Required


Collection Container: Plastic urine container

Specimen Volume: 5-25 mL

Collection Instructions:

  1. Collect 5-25 mL random urine without preservative.
  2. Ship frozen in a plastic container.

 

NOTE: Submit with specimen:

1. Clinical history/Preliminary diagnosis

 

-Because URSO can mask detection of bile acid synthetic defects it is preferable for patients to be off Urso or Actigall for 5 days before sample collection.

 

-If possible, send Urine & Serum (ZW166 - Bile Acids Serum, referral lab code 9001004). Urine is analyzed for all patients - if Urine shows evidence of a metabolic abnormality, Serum will be tested. Urine and serum must be ordered separately as they are 2 separate tests with separate charges.


Secondary ID

75012

Method Name

Fast Atom Bombardment-Mass Spectrometry (FAB-MS)

Reporting Name

Bile Acids, Urine

Specimen Type

Urine

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen (preferred)
  Ambient  48 hours
  Refrigerated  48 hours

Reject Due To

Hemolysis NA
Lipemia NA
Icterus NA
Other Collection in or on diaper or cotton balls

Clinical Information

Diagnostic testing in pediatric and adult patients presenting with conditions of cholestatic liver disease, neurological disease, or fat-soluble vitamin malabsorption of unknown etiology. Urine FAB-MS analysis provides a rapid and cost-effective means of diagnosing the most common of the genetic defects in the metabolism of cholesterol to the primary bile acids. Mass spectrometry testing may be used to monitor the biochemical response to primary bile acid therapy and to help in decisions on dose adjustments, where compliance should lead to a reduction in levels of atypical bile acids.

Method Description

Application of liquid secondary ionization mass spectrometry using fast atom bombardment (FAB-MS) ionization to detect the negative ions associated with the presence of increased concentrations of atypical bile acids in urine resulting from the loss of activity of one of the key enzymes that catalyze the production of normal primary bile acids by the liver. Each enzyme defect yields a distinct and specific mass spectrum that permits the diagnosis of the genetic defect.

Day(s) Performed

Friday

Report Available

7 to 30 days

Performing Laboratory

Cincinnati Childrens Hosp Med CTR Core Laboratories

Test Classification

This test was developed and its performance characteristics were determined and validated by the Clinical Mass Spectrometry Laboratory at Cincinnati Childrens Hospital Medical Center. It has not been cleared or approved by the U. S. Food and Drug Administration. This laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA 88) as qualified to perform high-complexity laboratory testing.

CPT Code Information

83789

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FBAC Bile Acids, Urine 49254-6

 

Result ID Test Result Name Result LOINC Value
FBAC Bile Acids, Urine 49254-6