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T-cell subset analysis (CD4+, CD8+, and total T-cells) in peripheral blood

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

This test measures different types of T-cells in your blood, which play a key role in your immune system. T-cells help your body fight infections and respond to diseases.

Quick summary

["Understanding your T-cell counts can help assess your immune health and response to treatments."]

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

Key facts at a glance

LOINC
52997-4
Short code
TdT Cells NFr Fld FC
Synonyms
TdT Cells NFr Fld FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
86430
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to evaluate your immune system function, especially if you have conditions like HIV/AIDS, cancer, or autoimmune diseases. It can also help monitor treatment effectiveness or diagnose immune-related disorders.

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 a few minutes and is generally comfortable.

What the Results Mean

Your results will show counts for different T-cell types, including CD4+ (helper T-cells), CD8+ (cytotoxic T-cells), and total T-cells. These numbers help determine if your immune system is functioning normally or if there are imbalances that need attention.

Common Conditions Monitored

Low or abnormal T-cell counts may indicate weakened immunity, infections, or certain cancers. High counts might suggest overactive immune responses or other underlying health issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

T-cell subset count

Frequently asked questions

What does a normal T-cell count range look like?
There’s no single ‘normal’ range for all patients because it varies by age, health status, and lab methods. Your doctor will compare your results to your baseline or specific clinical guidelines relevant to your condition.
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 healthcare provider 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 this test. No fasting is required, unlike some other blood tests.
  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