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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, red blood cells, and sometimes a breakdown of different types of white blood cells. It helps assess conditions affecting the brain and spinal cord.

Quick summary

["A CSF cell count helps diagnose or monitor infections, inflammation, or bleeding in the central nervous system."]

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

Key facts at a glance

LOINC
43950-5
Short code
CD2BF
Synonyms
CD2 Cells # Fld
Category
chemistry
Sample
serum
Container
Sterile leak-proof container for body fluid collection; EDTA (lavender-top) tube preferred for flow cytometry to prevent cell clumping and preserve surface antigen integrity
Units
N/A
Ref low
60
Ref high
85
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Flow cytometry using fluorescently labeled monoclonal antibodies targeting CD2 surface marker, typically with CD45 and side scatter gating to identify lymphocyte populations
CPT
88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker) + 88185 (each additional marker)
SNOMED
115780007 |CD2 antigen positive cell count (procedure)|
Specimen volume
Minimum 1-2 mL of body fluid; larger volumes (3-5 mL) preferred when feasible for accurate cell enumeration and to account for dilution
Stability
Specimen should be processed within 2-4 hours of collection at room temperature (18-25°C). If delayed, store at 2-8°C for up to 24 hours; however, viability and antigen expression may decrease. Refrigerated transport recommended if processing delayed.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–48 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like headaches, neck stiffness, confusion, fever, or neurological issues. It’s often used to investigate conditions such as meningitis, encephalitis, multiple sclerosis, or subarachnoid hemorrhage. Sometimes, it’s done as part of a routine evaluation for unexplained headaches or other neurological concerns.

What to Expect Before the Test

You’ll likely have a lumbar puncture (spinal tap) performed, where a needle is inserted into your lower back to collect CSF. The procedure is usually quick but may cause mild discomfort. You may be asked to lie still for a short time afterward. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

The results show the total cell count and sometimes the types of cells present. High cell counts (especially white blood cells) may indicate infection, inflammation, or bleeding. Low cell counts might suggest normal findings or conditions like certain brain tumors. Your doctor will interpret the results in the context of your symptoms and medical history.

Common Conditions This Test Helps Diagnose

This test can help diagnose or monitor conditions like bacterial or viral meningitis, multiple sclerosis, subarachnoid hemorrhage, encephalitis, Guillain-Barré syndrome, or other inflammatory or infectious processes in the central nervous system.

Reference range

Reference ranges for CD2+ cells in body fluid vary by fluid type and clinical context. Generally, CD2+ T-cells comprise 60-85% of total lymphocytes in peripheral blood. In body fluids, values are interpreted in conjunction with clinical presentation, total cell count, and cytological findings.N/A

Specimen: serum

No special patient preparation required. Inform the laboratory of any recent immunosuppressive therapy, chemotherapy, or bone marrow transplantation, as these may significantly alter CD2+ cell counts.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Cell Count

Frequently asked questions

How often does this test cause discomfort or side effects?
Most people experience only mild discomfort during the lumbar puncture, which is a quick procedure. Some may feel a slight pinch or pressure. Rarely, there could be temporary headaches or bruising at the injection site. If you experience severe pain, dizziness, or signs of infection (like fever or redness), contact your doctor immediately.
What should I do if I have a high or low cell count on this test?
A high cell count often signals an infection, inflammation, or bleeding. A low cell count may indicate normal findings or certain neurological conditions. Your doctor will discuss the results with you and may recommend further testing or treatments based on the cause. Follow their advice closely.
Can I drink alcohol before this test?
It’s best to avoid alcohol before the test, as it may affect your blood pressure or increase the risk of bleeding during the lumbar puncture. However, your doctor will provide specific instructions based on your health and any medications you’re taking.
  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