Cerebrospinal Fluid Cell Count (with Differential)
This test measures the number of cells in your cerebrospinal fluid (CSF), which is the fluid surrounding your brain and spinal cord. It helps assess for inflammation, infection, or other abnormalities in the central nervous system.
["A high cell count may signal an underlying issue requiring further evaluation."]
Key facts at a glance
- LOINC
- 52875-2
- Short code
- CD1aCSF
- Synonyms
- CD1a Cells NFr CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube (polypropylene); specific tube type may vary by laboratory protocol (e.g., tube 2-4 for cell analysis)
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Flow cytometry using fluorochrome-conjugated monoclonal antibodies against CD1a surface marker
- CPT
- 88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker) plus 88185 (each additional marker)
- SNOMED
- 252390007 |Cerebrospinal fluid specimen|; 116646008 |Flow cytometry, immunophenotyping|
- Specimen volume
- 1-2 mL of cerebrospinal fluid; minimum 0.5 mL for flow cytometry analysis
- Stability
- Specimen should be processed within 1-2 hours of collection at room temperature (18-25°C). If processing is delayed, refrigerate at 2-8°C and analyze within 4 hours; viability decreases significantly beyond this timeframe.
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you have symptoms like headaches, neck stiffness, confusion, fever, or neurological concerns. It’s often used to diagnose conditions such as meningitis, brain tumors, or multiple sclerosis.
What to Expect Before the Test
You’ll likely have a lumbar puncture (spinal tap) where a small needle is inserted into your lower back to collect CSF. The procedure is quick but may cause mild discomfort. You may be asked to lie still afterward.
What the Results Mean
The test includes a total cell count and a breakdown of cell types (e.g., white blood cells, red blood cells, or specialized immune cells). Abnormal results may indicate infection, bleeding, or other neurological issues.
Common Conditions Monitored
This test helps diagnose or monitor conditions like bacterial or viral meningitis, encephalitis, subarachnoid hemorrhages, or certain autoimmune diseases affecting the brain.
Reference range
CD1a-positive cells are typically absent or present in very low numbers (<1%) in normal cerebrospinal fluid. Reference values should be established by individual laboratories based on their patient population and analytical method.N/A
No special patient preparation is required prior to lumbar puncture. Standard aseptic technique must be used during CSF collection to prevent contamination.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CSF Cell Count
Frequently asked questions
What causes a high or low cell count in CSF?
Does this test hurt?
Can I eat or drink before the 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