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Cerebrospinal Fluid Cell Count (with Differential)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of cells in your cerebrospinal fluid (CSF), including white blood cells broken down by type (neutrophils, lymphocytes, etc.). It helps assess conditions affecting the brain and spinal cord.

Quick summary

["A CSF cell count helps diagnose infections, inflammation, or other issues in your nervous system."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
8118-2
Short code
CD2
Synonyms
CD2 Cells NFr Bld
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA) tube for whole blood collection; alternatively heparinized tubes may be used for flow cytometry applications
Units
N/A
Ref low
73
Ref high
89
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Flow cytometry using fluorescently labeled monoclonal antibodies against CD2 surface marker, typically analyzed on a flow cytometer with leukocyte gating strategies
CPT
86355
SNOMED
269741003
Specimen volume
3-5 mL whole blood for adults; minimum 1 mL for pediatric patients
Stability
Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C); do not refrigerate as this may affect cell viability and marker expression
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

CSF is the fluid that surrounds your brain and spinal cord. When your body has an infection, injury, or disease affecting these areas, the fluid may contain abnormal numbers of cells. This test helps doctors determine whether you have conditions like meningitis, multiple sclerosis, or other neurological problems.

What to Expect Before the Test

You’ll likely have a small needle inserted into your spine (usually in the lower back) to collect a sample of CSF. The procedure is quick but may cause mild discomfort. No special preparation is needed, but inform your doctor about any medications or health conditions you have.

How the Test Works

The collected CSF is sent to a lab, where it is examined under a microscope to count and identify different types of cells. This process helps doctors analyze the presence of abnormal cells, which can indicate inflammation, infection, or other underlying issues.

Possible Results and Next Steps

If your results show an elevated number of white blood cells (especially neutrophils), it may suggest an infection like bacterial meningitis. If lymphocytes are high, it could indicate viral infections or autoimmune diseases. Your doctor will discuss the results with you and may recommend further testing or treatment.

Reference range

Reference ranges vary by laboratory; CD2 is normally expressed on approximately 73-89% of peripheral blood T lymphocytes and represents a major T-cell subset along with CD3 and CD5N/A

Specimen: whole-blood

No special patient preparation required. Patient should be well-hydrated. Inform clinician of any recent immunosuppressive therapy, chemotherapy, or corticosteroid use as these may affect lymphocyte subset counts

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

CSF Cell Count

Frequently asked questions

What could cause abnormal CSF cell counts?
Abnormal CSF cell counts can result from infections (such as meningitis or encephalitis), inflammatory conditions (like multiple sclerosis), traumatic brain/spinal cord injuries, or certain cancers affecting the nervous system. High white blood cell counts often point to infection, while high lymphocytes may suggest autoimmune or chronic diseases.
How often is this test performed?
This test is typically performed only when doctors suspect a neurological condition, such as severe headaches, fever with neurological symptoms, or signs of inflammation in the brain/spinal cord. It’s not a routine screening test.
Can I eat or drink before this test?
You can eat and drink normally before the test, as it doesn’t require fasting. However, inform your doctor about any medications you’re taking, as some may affect the procedure or results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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