Lymphocyte Subset Count: CD3+, CD8+, and CD4+ Cells in Blood
This test measures specific types of white blood cells (lymphocytes) in your blood, focusing on CD3, CD4, and CD8 markers that help identify immune cell populations.
["Understanding your immune cell composition can help diagnose or monitor conditions affecting your immune system."]
Key facts at a glance
- LOINC
- 106911-1
- Short code
- CD3CD8BAL
- Synonyms
- CD3+CD8+ Cells/lymph NFr BAL FC
- Category
- chemistry
- Sample
- serum
- Container
- Sterile BAL collection container; transport in sterile saline or RPMI medium at room temperature
- Units
- N/A
- Ref low
- 40
- Ref high
- 65
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- flow-cytometry
- CPT
- 86359
- SNOMED
- 122548009
- Specimen volume
- Minimum 5-10 mL of BAL fluid required for flow cytometry analysis
- Stability
- Process within 2-4 hours of collection; do not freeze; store at room temperature (20-25°C) or refrigerate (2-8°C) if immediate processing not possible
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does Each Marker Represent?
CD3 is a marker found on most T-cells, which play a key role in immune responses. CD4+ T-cells help regulate immune activity, while CD8+ T-cells are involved in destroying infected or cancerous cells. These markers help assess overall immune health and identify immune deficiencies or overactivity.
Why Might This Test Be Ordered?
Your healthcare provider may order this test to evaluate immune function, diagnose conditions like HIV/AIDS, check for immune deficiencies (e.g., severe combined immunodeficiency), or monitor treatment responses in diseases affecting the immune system.
Sample Collection and Preparation
A blood sample is drawn from a vein, typically in your arm. The blood is processed to separate the white blood cells, which are then analyzed for these specific markers. No special preparation is needed, but fasting may not be required unless specified by your doctor.
What to Expect During the Test
The procedure is quick and usually painless. You may feel a slight pinch when the needle is inserted, but most people tolerate it well. The blood sample is then sent to a lab for detailed analysis.
Reference range
CD3+CD8+ T lymphocytes typically represent 40-65% of total lymphocytes in normal bronchoalveolar lavage (BAL) fluid. Results reported as percentage of lymphocytes or absolute count.N/A
No special patient preparation required. Bronchoalveolar lavage performed during bronchoscopy procedure. Patient should follow pre-bronchoscopy fasting and medication instructions as directed by physician.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Lymphocyte Subset Analysis
Frequently asked questions
How long does it take to get results from this test?
Can I eat or drink before this test?
What does it mean if my CD3, CD4, or CD8 levels are outside of normal ranges?
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