B-cell Lymphocyte Count (Absolute) from Peripheral Blood
This test measures the number of B cells, a type of white blood cell important for making antibodies that help fight infections and diseases like cancer.
["B-cell counts help doctors assess immune function and monitor conditions affecting white blood cells."]
Key facts at a glance
- LOINC
- 107082-0
- Short code
- CD20BMFC
- Synonyms
- CD20 Cells NFr Mar FC
- Category
- chemistry
- Sample
- serum
- Container
- Sterile bone marrow aspirate collected in sodium heparin (green-top) or EDTA (lavender-top) anticoagulant tube for flow cytometry. EDTA preferred for immunophenotyping stability.
- Units
- N/A
- Ref low
- 2
- Ref high
- 10
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- flow-cytometry
- CPT
- 88184
- SNOMED
- 395146001
- Specimen volume
- 1-3 mL of bone marrow aspirate (first pull preferred for accurate cellularity). Minimum 0.5 mL acceptable for flow cytometric analysis.
- Stability
- Specimen should be processed within 24 hours of collection when stored at room temperature (18-25°C). Refrigeration (2-8°C) extends viability to 48 hours but may affect cell viability. Do not freeze. Viability decreases significantly beyond 48 hours.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–48 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test to evaluate your immune system, diagnose or monitor conditions such as immune deficiencies, infections, or certain cancers (e.g., lymphoma). It can also help track responses to treatments like chemotherapy or immune-modifying therapies.
Sample Collection and Preparation
A small amount of blood is drawn from a vein in your arm. The blood is processed to separate white blood cells, including B cells, for counting.
What to Expect Before the Test
No special preparation is needed, but inform your healthcare provider about any medications or conditions that might affect results, such as recent infections or immune-suppressing treatments.
What the Results Mean
Results show the absolute number of B cells per microliter of blood. Low counts may indicate immune disorders, while very high counts could suggest certain blood disorders or overactive immune responses.
Reference range
CD20+ B-lymphocytes typically represent 2-10% of nucleated bone marrow cells in healthy adults. Absolute counts and percentages should be interpreted in conjunction with complete bone marrow differential, clinical findings, and morphologic evaluation. Age-adjusted reference ranges apply, with higher percentages observed in pediatric populations.N/A
No special patient preparation required. Recent therapy with anti-CD20 monoclonal antibodies (rituximab, obinutuzumab, ofatumumab) may significantly affect results and should be documented. Bone marrow aspiration is performed by qualified physician under local anesthesia.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
B-cell count
Frequently asked questions
What causes low B-cell counts?
How long does it take to get results?
Can I eat or drink before 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