Fast Atom Bombardment-Mass Spectrometry (FAB-MS)
FAB Testing
Bile Acids Urine
FBAC
.
Urine
Collection Container: Plastic urine container
Specimen Volume: 5-25 mL
Collection Instructions:
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.
1 mL
Hemolysis | NA |
Lipemia | NA |
Icterus | NA |
Other | Collection in or on diaper or cotton balls |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Frozen (preferred) | ||
Ambient | 48 hours | ||
Refrigerated | 48 hours |
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.
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.
Friday
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.
83789
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
FBAC | Bile Acids, Urine | 49254-6 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
FBAC | Bile Acids, Urine | 49254-6 |