Farnesoid X Receptor (FXR) Activity/Function Biomarker (Serum)
This test measures the activity of Farnesoid X Receptor (FXR), a protein involved in regulating bile acid metabolism and liver function. It may be used to assess liver health or bile flow in certain conditions.
["This test helps evaluate how your body processes bile acids and may support liver function assessment."]
Key facts at a glance
- LOINC
- 102277-1
- Short code
- D farinae IgE RAST
- Synonyms
- D farinae IgE RAST
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- rast
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is Farnesoid X Receptor (FXR)?
FXR is a receptor in your liver and intestines that helps control the production and excretion of bile acids, which are essential for digesting fats. When FXR is active, it signals the body to adjust bile acid levels, supporting liver health and preventing potential buildup that could harm the organ.
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you have symptoms or conditions linked to bile acid dysfunction, such as liver disease, gallbladder issues, or metabolic disorders. It could also be part of a broader evaluation for unexplained liver concerns or bile flow problems.
How Is the Test Performed?
A blood sample is drawn from a vein in your arm. The serum portion is then analyzed to measure FXR activity levels using specialized laboratory techniques, such as immunoassay or enzymatic methods.
What Does a Result Mean?
Results may indicate whether FXR is functioning normally or if there are disruptions in bile acid metabolism. Abnormal findings could suggest conditions affecting liver function, bile flow, or metabolic regulation, though interpretation depends on clinical context and other test results.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
FXR activity testing is primarily used to investigate liver and bile-related disorders. Elevated or altered FXR activity might point to conditions like primary biliary cholangitis (a chronic liver disease) or other metabolic or genetic disorders affecting bile acid processing. It may also help monitor treatment responses in patients with known liver or gallbladder conditions.
Short name
FXR Activity Test
Frequently asked questions
What does an abnormal FXR activity result mean?
How often should I get this test?
Can lifestyle changes affect FXR activity?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy