CD19+ Cell Count in Cerebrospinal Fluid (CSF)
This test measures the number of CD19+ cells, a type of immune cell found in the cerebrospinal fluid (CSF). It helps assess immune cell presence in the central nervous system.
["Evaluates immune cell activity in CSF for conditions affecting the brain and spinal cord."]
Key facts at a glance
- LOINC
- 43972-9
- Short code
- CD19 CSF
- Synonyms
- CD19 Cells # CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube; polystyrene or polypropylene tube suitable for flow cytometry analysis. Tube should be free of preservatives that may affect cell viability.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Flow cytometry (immunophenotyping)
- CPT
- 86355
- SNOMED
- 122615007
- Specimen volume
- 1-3 mL of cerebrospinal fluid (minimum 0.5 mL for flow cytometric immunophenotyping)
- Stability
- Specimen should be processed within 1-4 hours of collection for optimal cell viability. If immediate processing is not possible, refrigerate at 2-8°C and analyze within 24 hours. Do not freeze.
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms like headaches, neurological issues, or signs of an immune response in the brain or spinal cord. It could be used to investigate conditions such as infections, inflammatory diseases, or certain cancers like lymphoma.
What to Expect Before the Test
No special preparation is needed. A small amount of CSF is collected through a procedure called a lumbar puncture (spinal tap), where a needle is inserted into the spinal canal. You may feel pressure or mild discomfort, but it’s usually well-tolerated.
What the Test Results Mean
The results show the count of CD19+ cells, which are a subset of B lymphocytes—a key part of the immune system. Abnormal counts may indicate immune activation, infection, or other neurological conditions.
Common Conditions Monitored
This test is often used to monitor conditions like multiple sclerosis, certain infections (e.g., meningitis), or immune-related disorders affecting the central nervous system.
Reference range
Reference range not established; CD19+ B-lymphocytes are typically absent or present in very low numbers in normal cerebrospinal fluid. Results should be interpreted in clinical context.N/A
No special patient preparation required. Inform the ordering physician of any recent intrathecal medications, recent lumbar punctures, or active CNS infections as these may affect results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
CD19+ Lymphocyte Count (CSF)
Frequently asked questions
What does a high CD19+ cell count in CSF mean?
How is this test different from blood CD19+ tests?
Can I eat or drink before 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