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Lymphocyte Subset Count in Cerebrospinal Fluid (CSF) – Absolute Counts

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of lymphocytes (a type of white blood cell) in your cerebrospinal fluid (CSF). It helps assess immune activity in the brain and spinal cord.

Quick summary

["Understanding your CSF immune response through lymphocyte levels."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30414-7
Short code
Lymph Abn NFr CSF
Synonyms
Lymph Abn NFr CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to investigate conditions affecting the central nervous system (CNS), such as infections (e.g., meningitis), inflammatory diseases (e.g., multiple sclerosis), or certain cancers (e.g., lymphoma). It can also help monitor treatment progress in these conditions.

What to Expect Before the Test

You’ll likely have a lumbar puncture (spinal tap) to collect CSF. This procedure involves inserting a needle into your lower back. You may feel pressure or mild discomfort, but it’s usually brief. Rest for a few hours afterward to avoid headaches.

What the Results Mean

Results show absolute lymphocyte counts in CSF, which can help determine if inflammation, infection, or other immune activity is present. Abnormal levels may suggest specific conditions, but interpretation depends on clinical context (e.g., symptoms, other tests).

Common Conditions Linked to Abnormal Results

High lymphocyte counts might indicate chronic inflammation, autoimmune diseases, or certain infections. Low counts could suggest immune suppression or rare disorders. Always discuss results with your doctor.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CSF Lymphocyte Count

Frequently asked questions

What does a ‘lymphocyte subset’ mean in this test?
This test measures the total absolute count of lymphocytes (a broad category of white blood cells) in CSF, not specific subtypes (e.g., T-cells, B-cells). Subtypes would require additional specialized testing.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing and clinical urgency. Follow-up with your doctor to discuss findings.
Can I eat or drink before this test?
No special preparation is needed. You may drink water but avoid caffeine or alcohol before the lumbar puncture to reduce discomfort.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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