B-cell Lymphocyte Count (Absolute, Peripheral Blood)
This test measures the number of B cells, a type of white blood cell involved in immune responses, found in your blood.
["Understanding your B-cell count helps assess immune function and detect conditions like infections or immune disorders."]
Key facts at a glance
- LOINC
- 51264-0
- Short code
- CD19TISS
- Synonyms
- CD19 Cells NFr Tiss
- Category
- chemistry
- Sample
- serum
- Container
- Sterile container with 10% neutral buffered formalin for IHC; or RPMI/culture medium for flow cytometry; tissue should be fresh or properly preserved
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Immunohistochemistry (IHC) or Flow Cytometry with CD19-specific monoclonal antibodies
- CPT
- 88342 (immunohistochemistry) or 88184-88189 (flow cytometry panel)
- SNOMED
- 38341003 | 116913000
- Specimen volume
- Adequate tissue sample size determined by clinical procedure (biopsy or resection specimen)
- Stability
- Formalin-fixed paraffin-embedded (FFPE) tissue: stable indefinitely at room temperature; Fresh tissue for flow cytometry: process within 24-48 hours at 2-8°C
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–168 hours
- Order
- routine
Why This Test Matters
B cells are crucial for producing antibodies that fight infections and help your body remember past illnesses. Low or high counts may signal immune system issues, such as infections, autoimmune diseases, or certain cancers like lymphoma.
When You Might Need This Test
Your doctor may order this test if you have symptoms like frequent infections, unexplained fatigue, swollen lymph nodes, or if you’re undergoing treatment for conditions like leukemia or autoimmune diseases.
How the Test Works
A small sample of your blood is taken and analyzed to count the B cells. This is typically done using a blood test that separates and counts different types of white blood cells.
What to Expect Before the Test
No special preparation is needed. You may have a slight pinch when the blood is drawn, but it usually takes only a few minutes. Avoid strenuous activity or eating heavy meals before the test.
Reference range
Reference ranges vary by tissue type and laboratory methodology; results should be interpreted in conjunction with clinical findings and histopathological contextN/A
No special patient preparation required; tissue samples are obtained via biopsy or surgical excision following standard surgical protocols
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
B-cell count
Frequently asked questions
A low B-cell count may indicate immune deficiencies, infections, or certain cancers. A high count could suggest chronic infections, autoimmune diseases, or overactive immune responses. Always discuss results with your healthcare provider.
What Does a Low B-Cell Count Mean?
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