B-cell CD19/CD38 Immunophenotyping (Flow Cytometry)
This test measures the presence and proportion of specific immune cells (B-cells) marked by CD19 and CD38 proteins, often used to evaluate conditions affecting the bone marrow or immune system.
["Assesses immune cell health with markers linked to B-cell activity and maturity."]
Key facts at a glance
- LOINC
- 26562-9
- Short code
- CD19CD38
- Synonyms
- CD19+CD38+ Cells NFr Spec
- Category
- chemistry
- Sample
- serum
- Container
- Heparinized (sodium heparin or lithium heparin) tube preferred; EDTA tube acceptable. Lavender-top (EDTA) or green-top (heparin) vacuum collection tubes
- Units
- N/A
- Ref low
- 2
- Ref high
- 15
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–999 years
- Method
- Flow cytometry using fluorescently-labeled monoclonal antibodies (CD19 and CD38) for immunophenotyping of B-lymphocyte subpopulations
- CPT
- 86355
- SNOMED
- 395121009
- Specimen volume
- 3-5 mL whole blood (minimum 1 mL for pediatric samples)
- Stability
- Specimen must be processed within 24-48 hours of collection when stored at room temperature (20-25°C). Refrigerated storage (2-8°C) may extend stability to 48-72 hours. Do not freeze
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test to diagnose or monitor conditions such as leukemia, lymphoma, or other blood disorders. It helps track how well treatment is working or if abnormal cells are present in your blood or bone marrow.
How the Test Works
A small blood sample is taken, and special dyes (antibodies) bind to CD19 and CD38 proteins on B-cells. A machine then analyzes the cells under a microscope to count and identify them.
Sample Collection
You’ll have a needle inserted into a vein (usually in your arm) to draw blood. This is quick and usually doesn’t cause discomfort. You may feel a slight pinch or sting.
Preparation
No special preparation is needed. You can eat, drink, or take medications as usual on the day of the test.
Reference range
Reference ranges vary by laboratory; typically expressed as percentage of total lymphocytes or absolute count (cells/μL). Normal adult reference range for CD19+CD38+ B-cells is generally 2-15% of total lymphocytes or 20-300 cells/μLN/A
No special preparation required. Patient should be well-hydrated. Inform provider of recent corticosteroid use, chemotherapy, or immunosuppressive medications as these may affect lymphocyte counts
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
B-cell marker analysis
Frequently asked questions
What does a positive result mean?
How long does it take to get results?
Is there any risk or discomfort with 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 15, 2026. · Read our editorial policy