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B-cell count (absolute, confirmed) from whole blood

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of B-cells (a type of white blood cell) in your blood to help diagnose or monitor conditions like immune disorders, infections, or certain cancers.

Quick summary

["B-cell counts help doctors assess immune function and identify potential health issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
51354-9
Short code
CD19CD58BM
Synonyms
CD19+CD58+ Cells NFr Mar
Category
chemistry
Sample
serum
Container
Heparinized bone marrow aspirate collected in sodium heparin (green-top) or EDTA (lavender-top) tube; sterile collection tube for bone marrow specimens
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Flow cytometry (multiparametric immunophenotyping using fluorescently labeled monoclonal antibodies against CD19 and CD58 surface markers)
CPT
88184
SNOMED
441829007
Specimen volume
1-3 mL of bone marrow aspirate in anticoagulant-containing tube; minimum 0.5 mL for adequate analysis
Stability
Specimen should be processed within 24 hours of collection when stored at room temperature (18-25°C); viability and antigen expression may decline beyond 24-48 hours
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
24–72 hours
Order
routine

Why This Test Is Done

Doctors may order a B-cell count to evaluate symptoms such as frequent infections, unusual fatigue, swollen lymph nodes, or unexplained weight loss. It’s also used in the diagnosis and monitoring of conditions like chronic lymphocytic leukemia (CLL), lymphoma, or autoimmune diseases such as lupus or rheumatoid arthritis.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood, which usually takes about 5 minutes. You can eat and drink normally before the test.

What the Test Results Mean

Results are typically reported as the absolute number of B-cells per microliter (cells/µL) of blood. Very high or very low counts can indicate underlying health concerns, but individual results depend on your overall health and medical history.

Possible Conditions Affecting Results

High B-cell counts may suggest conditions like chronic lymphocytic leukemia or other lymphoproliferative disorders. Low counts could indicate immune deficiencies, infections, or certain medications that suppress the immune system.

Reference range

Reference ranges for CD19+CD58+ cells in bone marrow vary by laboratory and clinical context; results should be interpreted in conjunction with clinical findings and complete immunophenotypic profile. Reported as percentage of total nucleated cells or absolute count when applicable.N/A

Specimen: serum

No special patient preparation required prior to bone marrow aspiration. Recent chemotherapy, immunotherapy, or immunosuppressive therapy may affect results and should be documented. Inform physician of any anticoagulant use.

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 B-cell count tell me about my health?
A B-cell count helps doctors understand how your immune system’s B-cells are functioning. It can reveal whether your immune system is overactive (as in some cancers or autoimmune diseases) or underactive (as in immune deficiencies).
How often should I get this test?
The frequency depends on your medical condition. If you have a chronic illness like CLL or lymphoma, your doctor may recommend regular monitoring. Otherwise, this test is usually done only when symptoms or test results suggest a need for evaluation.
Can lifestyle changes affect B-cell counts?
While diet and exercise can support overall immune health, they may not directly influence B-cell counts. However, certain medications (like steroids) or infections can temporarily affect blood cell counts, so always discuss any changes with your healthcare provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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