B-cell CD19/CD38 Immunophenotyping (Flow Cytometry) in Peripheral Blood
This test measures the presence and proportion of B-cells in your blood that express CD19 and CD38 markers, often used to assess immune cell populations or monitor conditions like lymphoma.
["Helps doctors evaluate immune health or track blood cancers."]
Key facts at a glance
- LOINC
- 51444-8
- Short code
- CD19CD38
- Synonyms
- CD19+CD38+ Cells Bld-aCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA (lavender/purple-top) or ACD (yellow-top) anticoagulant tube; specialized flow cytometry tubes may be required per laboratory specifications
- Units
- N/A
- Ref low
- 20
- Ref high
- 300
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Flow cytometry using fluorescently labeled monoclonal antibodies directed against CD19 and CD38 surface markers, with absolute count determination using counting beads or volumetric measurement
- CPT
- 86355
- SNOMED
- 271649006
- Specimen volume
- 3-5 mL of whole blood for adults; minimum 1 mL for pediatric samples
- Stability
- Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Do not refrigerate. Optimal analysis time is within 24 hours of collection.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test to diagnose or monitor conditions such as leukemia, lymphoma, or other immune system disorders. It can also help track responses to treatments like chemotherapy or stem cell transplants.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into a vein, usually in your arm, to draw a small amount of blood. The process takes about 5 minutes, and you may feel a brief pinch or discomfort.
What the Test Results Mean
Results show the percentage of B-cells expressing CD19 and CD38 markers. Abnormal levels may indicate immune disorders, cancers, or other blood-related conditions. Your doctor will interpret these results in the context of your overall health and medical history.
Common Uses and Conditions
This test is particularly useful in diagnosing hematologic malignancies (like B-cell lymphoma or leukemia), evaluating immune deficiencies, or monitoring immune cell activity in chronic diseases.
Reference range
Reference ranges vary by laboratory and instrument platform; typical adult absolute counts for CD19+CD38+ B lymphocytes range from approximately 20-300 cells/µL (0.5-5% of total lymphocytes). Pediatric values may differ.N/A
No special patient preparation required. Specimen should be collected prior to administration of immunosuppressive therapy or cellular products when possible to avoid interference with results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
B-cell marker test
Frequently asked questions
What does a ‘positive’ or ‘negative’ result mean?
How often will I need this test?
Is there any risk or side effect from this blood draw?
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