B-cell CD19 Cell Count (CNS Fluid)
This test measures the number of B-cells expressing the CD19 marker in your cerebrospinal fluid (CSF). It helps assess immune cell presence in the central nervous system, often used in diagnosing or monitoring conditions affecting the brain and spinal cord.
["CD19+ cells in CSF may indicate immune activity or abnormalities in the nervous system."]
Key facts at a glance
- LOINC
- 51334-1
- Short code
- CD19CD43CSF
- Synonyms
- CD19+CD43+ Cells NFr CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tubes (polypropylene); tube 3 or 4 typically used for cell-based immunology studies to minimize blood contamination
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Flow cytometry using fluorescently labeled antibodies against CD19 and CD43 surface markers, with cells identified and enumerated from cerebrospinal fluid
- CPT
- 86356
- SNOMED
- 395146002
- Specimen volume
- 1-3 mL of cerebrospinal fluid; minimum 0.5 mL recommended for adequate flow cytometry analysis
- Stability
- Specimen should be processed within 1-2 hours of collection for optimal cell viability; if delayed, refrigerate at 2-8°C and process within 4 hours maximum
- 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, neurological issues, or signs of an immune-related condition. It can help evaluate conditions such as multiple sclerosis, infections, or certain cancers that affect the brain or spinal cord.
What to Expect Before the Test
The test involves a lumbar puncture (spinal tap), where a small needle is inserted into your lower back to collect CSF. You may feel mild pressure or discomfort, but it’s usually quick and done under sterile conditions.
What the Results Mean
Results show the count of CD19+ cells in your CSF. Elevated counts may suggest inflammation, infection, or immune disorders, while normal levels help rule out certain conditions. Interpretation depends on clinical context and your symptoms.
Common Conditions Monitored
This test is often used to monitor conditions like multiple sclerosis, lymphoma, or infections (e.g., meningitis) that can alter immune cell presence in the CNS.
Reference range
Reference values are not well established for CD19+CD43+ cells in cerebrospinal fluid; results should be interpreted in the context of clinical findings, CSF total cell count, and comparison with peripheral blood lymphocyte subsetsN/A
No fasting required. Patient should be informed about the lumbar puncture procedure. Pre-procedure coagulation screening may be warranted in patients on anticoagulants or with coagulopathy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CD19+ Cells in CSF
Frequently asked questions
What does a high CD19+ cell count in CSF mean?
What does a normal CD19+ cell count in CSF mean?
How often is this test repeated?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy