B-cell Lymphocyte Count (Absolute)
This test measures the number of B-cells in your blood, which are a type of white blood cell important for fighting infections and producing antibodies.
["B-cells help your immune system respond to germs and protect you from illness."]
Key facts at a glance
- LOINC
- 14964-1
- Short code
- CD19ABN
- Synonyms
- CD19 Abn Bld Cells NFr
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA) tube for whole blood; sodium heparin tube acceptable for flow cytometry
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Flow cytometry (immunophenotyping)
- CPT
- 86356
- SNOMED
- 39078006
- Specimen volume
- 3-5 mL whole blood; minimum 1 mL for pediatric samples
- Stability
- Room temperature: 24 hours; refrigerated (2-8°C): 48 hours. Specimen should be processed within 24 hours for optimal viability of leukocyte surface markers.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test to evaluate your immune system, check for infections, monitor conditions like chronic lymphocytic leukemia (CLL), or assess immune responses before or after treatments such as chemotherapy or immunotherapy.
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 a blood sample. The process usually takes a few minutes, and you may feel a brief pinch or slight discomfort.
What the Test Results Mean
Results are typically reported as the absolute count of B-cells per microliter (µL) of blood. Low counts may indicate immune deficiencies or certain cancers, while high counts could signal overactive immune responses or conditions like CLL.
Common Conditions Monitored
This test is often used to monitor B-cell-related disorders, such as autoimmune diseases (e.g., lupus), infections (e.g., HIV), or cancers like lymphoma or leukemia.
Reference range
Reported as presence or absence of abnormal CD19-positive B-cell populations; quantitative results expressed as cells/μL or percentage of total lymphocytes. Reference values vary by clinical context and laboratory.N/A
No fasting required. Patients should inform their healthcare provider of any recent blood transfusions, immunosuppressive therapy, or vaccination history as these may affect B-cell populations.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
B-Cell Count
Frequently asked questions
What does a low B-cell count mean?
How is B-cell count tested?
Can diet or medications affect B-cell counts?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy