Absolute count of CD3+ and CD19+ lymphocytes (whole blood)
This test measures the number of specific types of white blood cells (lymphocytes) in your blood, focusing on CD3+ (T-cells) and CD19+ (B-cells). These cells play key roles in your immune system.
["Understanding your immune cell composition can help identify immune-related conditions."]
Key facts at a glance
- LOINC
- 106949-1
- Short code
- T Lymphocytes.CD3+CD19- NFr Mar FC
- Synonyms
- T Lymphocytes.CD3+CD19- NFr Mar 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, especially if you have symptoms like frequent infections, unexplained fatigue, or signs of immune disorders. It can also be part of a broader checkup for 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 your arm or hand to draw blood. The process usually takes a few minutes, and you may feel a brief pinch. If you’re nervous, let your healthcare provider know.
What the Results Mean
The results show the absolute counts of CD3+ and CD19+ cells in your blood. While these numbers help assess immune health, they’re interpreted in the context of your overall health and symptoms. Your doctor will discuss the results with you.
Common Conditions This Test Helps Diagnose
Abnormal counts of these cells can signal conditions like immune deficiencies, infections, or cancers such as lymphoma or leukemia. For example, low counts might indicate immune suppression, while high counts could suggest overactive immune responses or certain cancers.
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. CD3+ and CD19+ lymphocyte counts help identify whether your immune system is functioning normally or if there’s an imbalance that requires treatment. It’s often used alongside other tests to guide treatment decisions, especially in cancer care or for patients with chronic immune conditions.
Short name
Lymphocyte subset count
Frequently asked questions
What does a ‘normal’ result mean for this test?
Can lifestyle changes, like diet or exercise, affect these test results?
How often should I get this test?
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