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Lymphocyte Subpopulation Count: Lymphocytes (Serum/Plasma) with Flow Cytometry-Based Fractionation

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

This test measures different types of white blood cells called lymphocytes in your blood, broken down by their specific characteristics. It helps doctors understand your immune system’s composition.

Quick summary

["Understanding your immune cell balance can help diagnose or monitor immune-related conditions."]

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

Key facts at a glance

LOINC
17215-5
Short code
Lymphs CV/lymph NFr Bld
Synonyms
Lymphs CV/lymph NFr Bld
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to evaluate immune function, detect immune disorders, or assess responses to treatments like chemotherapy or immune-modifying therapies. It can also help diagnose conditions like leukemia, lymphoma, or autoimmune diseases.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into a vein (usually in your arm), and blood will be drawn into a tube. The process takes about 5 minutes. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

The test provides percentages or counts of different lymphocyte subtypes, such as T-cells, B-cells, and natural killer cells. Abnormal results may indicate immune deficiencies, infections, or diseases affecting lymphocyte function.

Common Conditions Monitored

This test is often used to monitor conditions like HIV/AIDS, certain cancers (e.g., lymphoma), or immune disorders (e.g., lupus). It can also help track how well treatments are working.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Interpretation of Results

Short name

Lymphocyte Subtype Analysis

Frequently asked questions

What does a ‘lymphocyte subpopulation’ mean?
Lymphocytes are a type of white blood cell with different roles in your immune system. This test breaks them down into subtypes (e.g., T-cells, B-cells) to see which types are most or least present, helping pinpoint potential issues in your immune system.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
You can eat and drink normally before the test, as no special diet or fasting is required. However, if you’re on blood thinners or have a history of bleeding disorders, let your doctor know before the procedure.
  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