Absolute count of CD3+ and CD19+ lymphocytes (whole blood)
This test measures the total number of two key immune cells—CD3+ T cells and CD19+ B cells—in your blood. These cells play vital roles in fighting infections and maintaining immune function.
Understanding your immune cell balance helps identify immune disorders or responses to treatment.
Key facts at a glance
- LOINC
- 106948-3
- Short code
- T Lymphocytes.CD3+CD19- NFr Spec FC
- Synonyms
- T Lymphocytes.CD3+CD19- NFr Spec 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
- 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
Your doctor may order this test if you have symptoms like frequent infections, unexplained fatigue, or immune-related conditions (e.g., autoimmune diseases). It can also assess immune function before or after treatments like chemotherapy or organ transplants.
What to Expect Before the Test
No special preparation is needed. You’ll have a simple blood draw, usually from a vein in your arm. The process takes a few minutes, and you may feel a slight pinch. The blood sample is sent to a lab for analysis.
What the Results Mean
Results show absolute counts of CD3+ T cells and CD19+ B cells, which help determine if your immune system is functioning normally or if abnormalities exist (e.g., low counts may indicate immune suppression). Your doctor will interpret these results in the context of your symptoms and medical history.
Common Conditions Linked to Abnormal Results
Low counts of these cells may suggest conditions like HIV/AIDS, certain cancers (e.g., lymphoma), or immune deficiencies. High counts could indicate overactive immune responses or certain infections. Always discuss results with your healthcare provider.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: This test is critical for diagnosing and monitoring immune-related disorders, guiding treatment decisions, and ensuring proper immune function in patients undergoing immunosuppressive therapies.
Short name
Lymphocyte subset count
Frequently asked questions
What does a low or high count of CD3+ or CD19+ lymphocytes mean?
Can lifestyle changes affect these test results?
Is this test covered by insurance?
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