Immunoglobulin M (IgM) to Colony-Stimulating Factor (CSF) Ratio in Serum/Plasma
This test measures the relative levels of Immunoglobulin M (IgM), a type of antibody, and Colony-Stimulating Factor (CSF), a protein that supports white blood cell production, in your blood. It helps assess immune function and response to infections or certain medical conditions.
["The IgM-CSF ratio can help identify immune system activity and potential infections or inflammatory responses."]
Key facts at a glance
- LOINC
- 21351-2
- Short code
- IgM CSF Ql IFE
- Synonyms
- IgM CSF Ql IFE
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immunofixation
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms like frequent infections, unexplained fatigue, or if you’re being evaluated for conditions affecting your immune system, such as chronic infections, autoimmune diseases, or certain cancers. It could also be part of monitoring treatment responses for conditions like leukemia or lymphoma.
What to Expect Before the Test
No special preparation is needed for this test. You’ll typically have a small needle inserted into a vein in your arm to draw blood. If you’re nervous, let your healthcare provider know so they can help make it more comfortable. Avoid alcohol for 24 hours before the test if instructed.
What the Test Results Mean
Results are usually reported as a ratio rather than absolute values. An abnormal ratio may suggest an overactive immune response, chronic infection, or other underlying health issues. Your provider will discuss the results with you in the context of your overall health and symptoms.
Common Conditions Monitored
This test may be used to monitor conditions like chronic infections (e.g., Epstein-Barr virus, hepatitis), autoimmune diseases (e.g., lupus), or to evaluate immune responses during treatments for blood cancers or immune disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated IgM-CSF ratio might indicate an active immune response, such as chronic infection or an autoimmune condition. A lower ratio could suggest immune suppression or other systemic issues. Always interpret results with your healthcare provider, as they consider your full medical history and symptoms.
Short name
IgM-CSF Ratio
Frequently asked questions
What does an abnormal IgM-CSF ratio indicate?
How often will I need this test?
Can lifestyle changes affect this test?
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