Monocyte to Neutrophil Ratio in Fluid (e.g., Serum/Plasma)
This test compares the relative amounts of monocytes and neutrophils in a body fluid sample, such as blood plasma or serum. It helps assess immune cell balance, which can be useful in diagnosing infections, inflammatory conditions, or other blood disorders.
["This ratio can provide insights into your immune response and potential health risks."]
Key facts at a glance
- LOINC
- 30437-8
- Short code
- Monos+Macros NFr Fld
- Synonyms
- Monos+Macros NFr Fld
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 86430
- 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
Why Is This Test Done?
Your healthcare provider may order this test to evaluate immune cell dynamics, especially if you have symptoms like persistent infections, unexplained fevers, or signs of inflammation. It may also be used in research or specialized clinical settings to monitor conditions affecting white blood cell counts.
What Does the Test Measure?
The test measures the relative proportions of monocytes (a type of white blood cell involved in immune response and inflammation) and neutrophils (a key white blood cell in fighting acute infections). The ratio is calculated by comparing these two cell types in your fluid sample.
How Is the Test Performed?
A blood sample is drawn, and the fluid portion (plasma or serum) is analyzed to count and compare the types of white blood cells present. Advanced laboratory techniques, such as flow cytometry or automated hematology analyzers, are typically used to differentiate these cells.
What Are Possible Results?
Results are presented as a ratio (e.g., 1:2 or 3:1), indicating the relative abundance of monocytes to neutrophils. There are no standard reference ranges because this test is often used in research or specialized clinical contexts rather than routine diagnostics.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Changes in the monocyte-to-neutrophil ratio can reflect underlying immune dysfunctions. For example, a higher ratio may suggest chronic inflammation or immune activation, while a lower ratio might indicate acute infection or suppressed immune response. This test is less commonly used in standard clinical practice but may be valuable in specific research or diagnostic scenarios.
Short name
Monocyte-Neutrophil Ratio (MNR) Fluid
Frequently asked questions
What does a high or low ratio mean?
Is this test covered by insurance?
How long does it take to 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