CD4 Cell Count in Cerebrospinal Fluid (CSF)
This test measures the number of CD4 immune cells in your cerebrospinal fluid (CSF). CD4 cells are a type of white blood cell that helps fight infections.
["CD4 cells in CSF help assess immune function in the central nervous system."]
Key facts at a glance
- LOINC
- 51308-5
- Short code
- CD4CD7CD26
- Synonyms
- CD4+CD7-CD26- Cells NFr CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube (polypropylene); sterile cryovial for flow cytometry samples. Tubes should be pre-coated with appropriate anticoagulant if needed.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Flow cytometry using multi-parameter immunophenotyping with fluorescently labeled antibodies against CD4, CD7, and CD26 surface markers
- CPT
- 88184
- SNOMED
- 415646004
- Specimen volume
- 1-2 mL of cerebrospinal fluid for flow cytometric immunophenotyping; minimum 0.5 mL acceptable
- Stability
- Process within 2-4 hours of collection for optimal viability. If delayed, refrigerate at 2-8°C for up to 24 hours. Avoid freezing unless using cryopreservation protocols.
- Hemolysis max
- 200
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test if you have symptoms or conditions that could affect your immune system in the brain or spinal cord, such as certain infections (e.g., meningitis, encephalitis) or autoimmune diseases. It can also be part of monitoring for conditions like HIV or other immune-related disorders.
What to Expect Before the Test
No special preparation is needed. The test involves a lumbar puncture (spinal tap), where a small needle is inserted into your lower back to collect a small amount of CSF. You may feel mild pressure or discomfort, but it usually doesn’t require sedation.
What Happens During the Test?
After the needle is inserted, a small amount of CSF is collected into a sterile container. The sample is then sent to a lab for analysis. The test typically takes a few minutes, and you’ll be able to return to your usual activities shortly afterward.
What Does the Test Result Mean?
Results are reported as the absolute count of CD4 cells per microliter (µL) of CSF. Lower counts may indicate immune dysfunction or inflammation in the central nervous system, while higher counts may suggest normal immune function or certain conditions.
Reference range
CD4+CD7-CD26- cells are typically absent or present in very low numbers in normal cerebrospinal fluid. Reference values are not well established; results should be interpreted in clinical context. Reported as cells/μL or percentage of total lymphocytes.N/A
No special patient preparation required. Informed consent may be necessary for CSF collection via lumbar puncture. Patient should remain still during procedure.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CD4 Cells in CSF
Frequently asked questions
What does a low CD4 cell count in CSF mean?
Can this test be done on other fluids besides CSF?
How often might I need 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