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Lymphocyte Subset Count: CD3+ Cells

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

This test measures the number of CD3+ cells, a key marker of T lymphocytes, which play a critical role in immune response. CD3+ cells are part of the white blood cell family and help identify and attack pathogens.

Quick summary

["CD3+ cells help assess immune function and identify immune-related conditions."]

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

Key facts at a glance

LOINC
103683-9
Short code
CD3HLADR BAL
Synonyms
CD3+HLA-DR+ Cells/lymph NFr BAL
Category
chemistry
Sample
serum
Container
Sterile, leak-proof bronchoalveolar lavage collection container; transported to laboratory in sterile conical tubes on wet ice for flow cytometry processing
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–99 years
Method
Flow cytometry using fluorescently labeled monoclonal antibodies against CD3 and HLA-DR surface markers, with subsequent analysis of lymphocyte-gated populations in bronchoalveolar lavage fluid
CPT
86356
SNOMED
395124002
Specimen volume
Minimum 10-20 mL of bronchoalveolar lavage fluid required for adequate lymphocyte subset analysis by flow cytometry
Stability
Specimen should be processed within 2-4 hours of collection for optimal lymphocyte viability and marker expression. If immediate processing is not possible, refrigerate at 2-8°C and process within 6 hours maximum. Do not freeze.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

What Is CD3+ Cell Count Used For?

Doctors may order a CD3+ lymphocyte count to evaluate immune health, especially when diagnosing immune deficiencies, autoimmune diseases, or conditions affecting the lymphatic system. It can also help monitor responses to treatments like chemotherapy or immune-modulating therapies.

How Is This Test Performed?

Blood is drawn from a vein, typically in your arm. The sample is then analyzed in a lab to count the CD3+ T lymphocytes among your white blood cells. Results are usually available within 1–3 business days.

What Might Abnormal Results Indicate?

Low CD3+ cell counts may suggest immune suppression, lymphoma, or other lymphoproliferative disorders. High counts could indicate chronic infections, certain cancers, or overactive immune responses. Your doctor will interpret results in the context of your overall health and symptoms.

Common Conditions Evaluated With This Test

This test is often used alongside other blood tests to diagnose or monitor conditions like HIV/AIDS, autoimmune diseases (e.g., rheumatoid arthritis), or cancers affecting the immune system (e.g., leukemia). It may also be part of a broader immune panel.

Reference range

Typically reported as a percentage of total lymphocytes. Reference ranges vary by laboratory; published studies generally report CD3+HLA-DR+ activated T lymphocytes in BAL fluid at less than 5% of total lymphocytes in healthy individuals, though laboratory-specific reference intervals should be applied.N/A

Specimen: serum

Patient preparation applies to the bronchoalveolar lavage procedure rather than blood draw. Patients should fast for at least 4-6 hours prior to bronchoscopy if sedation is planned. Inform the physician of all medications, especially anticoagulants, immunosuppressants, and recent corticosteroid use which may affect lymphocyte populations.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CD3+ Lymphocytes and Immune Function

Short name

CD3+ Lymphocyte Count

Frequently asked questions

Why might my doctor ask for this test?
Your doctor may recommend this test if you have symptoms like frequent infections, unexplained fatigue, or if you’re undergoing treatment that affects your immune system. It helps track how well your immune cells are functioning over time.
How do I prepare for this test?
No special preparation is needed, but avoid heavy meals or alcohol 24 hours before your blood draw. Wear a short-sleeved shirt for easy access.
Will the test hurt?
You may feel a slight pinch when the needle is inserted, but most people tolerate it well. The procedure takes only a few minutes, and most people experience minimal discomfort afterward.
  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