Cerebrospinal Fluid Cell Differential Count
This test measures the types and numbers of white blood cells found in your cerebrospinal fluid (CSF), which surrounds your brain and spinal cord. It helps assess for infections, inflammation, or other conditions affecting the central nervous system.
["This test helps diagnose or monitor conditions affecting your brain or spinal cord."]
Key facts at a glance
- LOINC
- 106946-7
- Short code
- CD2CD3BM
- Synonyms
- CD2+CD3+ Cells NFr Mar FC
- Category
- chemistry
- Sample
- serum
- Container
- Sterile bone marrow aspirate collected into a heparinized (sodium heparin or lithium heparin) tube or ACD (acid-citrate-dextrose) anticoagulant tube for flow cytometry analysis.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 86355
- SNOMED
- 396451008
- Specimen volume
- 1–3 mL of bone marrow aspirate collected in anticoagulant; minimum 0.5 mL may be acceptable for flow cytometric immunophenotyping.
- Stability
- Specimen should be processed within 24 hours of collection when stored at room temperature (18–25°C). If delayed, store at 2–8°C and process within 48 hours. Viability of cells may decline with prolonged storage.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–48 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test if you have symptoms like headaches, neck stiffness, confusion, fever, or neurological issues. It’s often performed when there’s suspicion of meningitis, brain tumors, multiple sclerosis, or other conditions that affect the CSF.
What Does the Test Involve?
A small amount of CSF is collected through a procedure called a lumbar puncture (spinal tap). The fluid is then examined under a microscope to count and identify different types of white blood cells, such as neutrophils, lymphocytes, and monocytes.
What Are Common Findings?
A normal CSF cell count typically shows very few white blood cells (usually under 5 per microliter). Elevated counts may indicate infections (e.g., bacterial or viral meningitis), inflammation, or other neurological disorders.
How Long Until Results Are Available?
Results are usually available within 1 to 2 business days, depending on lab processing times. Your doctor will discuss the findings with you during your follow-up visit.
Reference range
Reference ranges are laboratory-specific and depend on age. In healthy adults, CD2+CD3+ (pan T-lymphocyte) cells typically constitute approximately 15–40% of total nucleated bone marrow cells, but values vary by institutional protocol.N/A
No special patient preparation is required. Recent immunotherapy, chemotherapy, radiation, immunosuppressive therapy, corticosteroids, or bone marrow transplantation may alter results and should be documented.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CSF Cell Count
Frequently asked questions
How is CSF collected for this test?
Will the procedure hurt?
What are the risks or side effects of 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