Cerebrospinal Fluid (CSF) Cell Differential Count
This test measures the types and numbers of white blood cells found in your cerebrospinal fluid (the fluid surrounding your brain and spinal cord). It helps assess conditions affecting the central nervous system.
["Understanding your CSF cell count can help diagnose or monitor neurological issues."]
Key facts at a glance
- LOINC
- 106956-6
- Short code
- CD200CD19FC
- Synonyms
- Cells.CD200+CD19+ NFr Bld FC
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA) or specialized preservative tubes for flow cytometry (e.g., BD Vacutainer K2-EDTA); heparinized tubes may be acceptable depending on laboratory protocol.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- flow-cytometry
- CPT
- 88184 (flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only); additional CPT codes may include 88185 for each additional marker and 88187-88189 for interpretation services.
- SNOMED
- 444479003 |Measurement of lymphocyte subset (procedure)|; 397540009 |Flow cytometry (procedure)|
- Specimen volume
- Minimum 3-5 mL of whole blood for adults; 1-2 mL for pediatric patients. Larger volumes preferred for improved cell yield and accurate enumeration of rare populations.
- Stability
- Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Refrigeration (2-8°C) may extend stability up to 48-72 hours but may affect viability marker expression. Do not freeze.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
What Does This Test Measure?
The test identifies and quantifies different types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and possibly red blood cells) in your CSF. Each cell type can provide clues about underlying health conditions, such as infections, inflammation, or blood leakage into the brain.
Why Might You Need This Test?
A CSF cell differential is often ordered if you have symptoms like severe headaches, neck stiffness, confusion, fever, or neurological problems. It may also be used to monitor conditions like meningitis, multiple sclerosis, or brain tumors.
Preparation for the Test
No special preparation is needed. You may have a lumbar puncture (spinal tap) under sterile conditions, where a small amount of CSF is collected from your lower back. The procedure is usually quick and painless, though you may feel mild discomfort afterward.
What Are Possible Results?
Results vary widely depending on your health and diagnosis. A normal result typically shows few to no white blood cells in the CSF. Elevated counts of certain cells (e.g., high lymphocytes in multiple sclerosis or high neutrophils in infection) may indicate specific conditions.
Reference range
Reference ranges are laboratory-specific and depend on the flow cytometry panel, gating strategy, and antibody clones used. Results are typically reported as a percentage of CD200+CD19+ cells relative to total lymphocytes, total B cells (CD19+), or total nucleated cells. Establish reference interval with local healthy donor population.N/A
No special patient preparation is required. Patients should be well-hydrated. Recent transfusion, immunosuppressive therapy, corticosteroid use, chemotherapy, or immunotherapy may affect absolute counts and should be noted on the requisition.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal CSF cell counts can signal serious conditions, such as infections (e.g., bacterial or viral meningitis), autoimmune diseases (e.g., Guillain-Barré syndrome), or structural issues (e.g., brain tumors or bleeding). Your doctor will interpret results in the context of your symptoms and medical history.
Short name
CSF Cell Count
Frequently asked questions
What does a high or low cell count mean?
How often will I need this test?
Can I eat or drink before 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