CD19+ B-Cell Lymphocyte Count in Cerebrospinal Fluid (CSF)
This test measures the number of CD19+ cells, a type of immune cell found in the cerebrospinal fluid (CSF). CD19+ cells are part of the B-cell lineage and play a role in immune response.
["Assessing immune cells in your brain’s fluid to help diagnose or monitor conditions affecting the central nervous system."]
Key facts at a glance
- LOINC
- 51265-7
- Short code
- CD19CSF
- Synonyms
- CD19 Cells NFr CSF
- Category
- chemistry
- Sample
- csf
- Container
- Sterile CSF collection tube (polypropylene); tube #3 or #4 typically preferred for cell-based assays to minimize blood contamination.
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Flow Cytometry (Immunophenotyping)
- CPT
- 86356
- SNOMED
- 116859006
- Specimen volume
- 1-2 mL of cerebrospinal fluid; minimum 0.5 mL recommended for flow cytometry analysis.
- Stability
- Specimen should be processed within 1-2 hours of collection for optimal cell viability. If delay is anticipated, refrigerate at 2-8°C; do not freeze. Specimen should ideally be analyzed within 4 hours.
- 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 or conditions that suggest an immune-related issue in the central nervous system, such as certain types of meningitis, lymphoma, or other neurological disorders. It may also be used to monitor treatment responses in conditions like multiple sclerosis or other chronic inflammatory diseases affecting the brain.
What to Expect Before the Test
The test involves a lumbar puncture (spinal tap), where a small amount of CSF is collected from your lower back. You may feel mild pressure or discomfort during the procedure, but it is generally quick and done under sterile conditions. No special preparation is typically required, but inform your provider about any medications you’re taking.
What the Results Mean
The results indicate the presence and quantity of CD19+ cells in your CSF. Elevated levels may suggest an immune-mediated process, such as certain infections, inflammatory diseases, or malignancies involving B-cells. Lower than expected levels might indicate immune suppression or other conditions affecting B-cell populations.
Common Conditions Monitored or Diagnosed With This Test
This test is often used to diagnose or monitor conditions like B-cell lymphoma (such as primary central nervous system lymphoma), certain types of meningitis, autoimmune diseases affecting the CNS, or to evaluate responses to treatments targeting immune cells.
Reference range
CD19+ B-lymphocytes are typically absent or present in very low numbers in normal cerebrospinal fluid. Reference ranges vary by laboratory; results should be interpreted in the context of clinical findings.N/A
No special patient preparation is typically required. Informed consent may be necessary for lumbar puncture procedure. Patient should remain still during the procedure.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CD19+ cells are critical markers for B-cell lineage disorders. Elevated counts in CSF can indicate active immune pathology, such as infections, inflammatory diseases, or neoplastic processes. Conversely, reduced counts may reflect immune dysfunction or treatment effects. Interpretation requires clinical correlation with symptoms and other diagnostic findings.
Short name
CSF CD19+ Lymphocyte Count
Frequently asked questions
What does a high CD19+ cell count in CSF mean?
Does this test require fasting?
Can I take pain relievers before the lumbar puncture?
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