Cerebrospinal fluid (CSF) albumin-to-globulin ratio
This test measures the ratio of albumin to globulin proteins in cerebrospinal fluid, which helps assess the blood-brain barrier and potential inflammation or infection in the central nervous system.
["Understanding protein balance in your spinal fluid can help diagnose neurological conditions."]
Key facts at a glance
- LOINC
- 60615-2
- Short code
- CANS
- Synonyms
- Cd-ANS Skull XR
- Category
- chemistry
- Sample
- serum
- Container
- N/A (radiographic imaging procedure)
- Units
- N/A
- Ref low
- 85
- Ref high
- 105
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 5–99 years
- Method
- xr-measured
- CPT
- 70260
- SNOMED
- 168537006
- Specimen volume
- N/A
- Stability
- N/A
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 1–4 hours
- Order
- routine
What Is the Purpose of This Test?
Doctors may order this test to evaluate conditions like multiple sclerosis, meningitis, brain tumors, or other neurological disorders that affect protein levels in the CSF. It can also help determine the extent of inflammation or blood leakage into the spinal fluid.
How Is the Test Performed?
A small amount of cerebrospinal fluid is collected through a procedure called a lumbar puncture (spinal tap). The fluid is then analyzed in a lab to measure albumin and globulin protein levels.
What Does the Test Result Mean?
A higher albumin-to-globulin ratio may suggest increased blood-brain barrier permeability, often seen in conditions like multiple sclerosis or infections. A lower ratio could indicate normal protein balance or other underlying issues like protein loss syndromes.
Common Conditions Evaluated
This test is often used alongside other CSF tests (like cell count or glucose) to diagnose or monitor neurological diseases. It helps distinguish between inflammatory, infectious, or neoplastic causes of altered CSF protein profiles.
Reference range
Reference range varies by age, sex, and population; clinical correlation and comparison with population-specific cephalometric norms recommendedN/A
No fasting required. Remove all metallic objects (jewelry, hair clips, dentures, eyeglasses) from head and neck area before imaging. Inform technologist if pregnant or if there is any possibility of pregnancy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CSF Alb:Glob Ratio
Frequently asked questions
Why might my doctor request this test?
What are typical reference ranges?
How soon will I get results?
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 16, 2026. · Read our editorial policy