B-cell Lymphocyte Count (Absolute)
This test measures the number of B cells, a type of white blood cell involved in immune response, found in your blood.
["B-cell counts help assess immune function and detect conditions like infections, autoimmune diseases, or cancers."]
Key facts at a glance
- LOINC
- 32525-8
- Short code
- CD19BM
- Synonyms
- CD19 Cells NFr Mar
- Category
- chemistry
- Sample
- serum
- Container
- Heparinized bone marrow aspirate in sterile tube (sodium heparin or lithium heparin); EDTA acceptable for some flow cytometry panels
- Units
- N/A
- Ref low
- 1
- Ref high
- 5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Flow cytometry (immunophenotyping) using fluorescently labeled anti-CD19 monoclonal antibodies
- CPT
- 88184
- SNOMED
- 116952009
- Specimen volume
- 1-3 mL bone marrow aspirate
- Stability
- Process within 24 hours of collection; store at room temperature (18-25°C); do not freeze; viability decreases significantly beyond 48 hours
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test to evaluate your immune system, diagnose or monitor conditions such as chronic infections, autoimmune disorders (e.g., lupus), or certain cancers (e.g., lymphoma). It may also be used before or after treatments that affect the immune system, like chemotherapy or radiation therapy.
What to Expect Before the Test
No special preparation is needed. The test is typically done by taking a small blood sample from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes.
What the Results Mean
Results are compared to standard ranges for healthy adults. Low counts may indicate immune deficiencies, infections, or certain cancers. High counts could suggest overactive immune responses or other conditions. Your provider will interpret results in the context of your overall health and medical history.
Common Conditions Affecting Results
Conditions that might lead to abnormal B-cell counts include chronic infections (e.g., HIV), autoimmune diseases (e.g., rheumatoid arthritis), or cancers like multiple myeloma or certain lymphomas. Medications, such as steroids or chemotherapy, can also influence these levels.
Reference range
CD19+ B lymphocytes in bone marrow: 1-5% of total nucleated cells; reference ranges vary by age and clinical context. Consultation with hematopathologist recommended for interpretation.N/A
No special patient preparation required. Inform physician of all medications, particularly recent chemotherapy, immunotherapy (e.g., rituximab), or immunosuppressive therapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal B-cell counts are critical for diagnosing and managing immune-related disorders. Low counts may necessitate further testing for infections, genetic disorders, or immune system suppression. High counts could signal immune activation or disorders like B-cell lymphoma. Regular monitoring is essential for patients undergoing treatments that impact immune function.
Short name
B-cell count
Frequently asked questions
How often will I need this test?
What are the normal ranges for B-cell counts?
Can lifestyle changes 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.
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