B-cell Lymphocyte Subset Count (CD19+ and CD23+ Cells)
This test measures the number of specific types of immune cells (B-cells) in your blood, focusing on cells marked by CD19 and CD23 markers. These markers help identify mature B-cells that play a role in antibody production and immune response.
["Understanding your B-cell counts can help assess immune function and diagnose or monitor conditions like chronic lymphocytic leukemia (CLL)."]
Key facts at a glance
- LOINC
- 47023-7
- Short code
- CD19CD23
- Synonyms
- CD19+CD23+ Cells NFr Spec
- Category
- chemistry
- Sample
- serum
- Container
- EDTA (lavender-top) anticoagulant tube for whole blood flow cytometry; ACD (yellow-top) tube acceptable alternative
- Units
- N/A
- Ref low
- 100
- Ref high
- 500
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Flow cytometry using fluorescently labeled monoclonal antibodies (CD19-FITC and CD23-PE) with whole blood lysis, followed by multiparameter analysis on a flow cytometer
- CPT
- 86356
- SNOMED
- 416409005
- Specimen volume
- 3-5 mL whole blood; minimum 1 mL for pediatric patients
- Stability
- Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-22°C); do not refrigerate as this may affect cell viability and surface marker expression. For delayed processing beyond 48 hours, consult laboratory for specific stability requirements.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms or risk factors for immune-related conditions, such as persistent infections, unexplained lymphadenopathy (swollen lymph nodes), or a family history of blood disorders. It may also be used to monitor treatment progress in conditions like CLL or other hematologic malignancies.
What to Expect Before the Test
No special preparation is typically needed. You may have a simple blood draw, often done in a clinic or lab. If you’re on blood-thinning medications, let your provider know before the test.
What the Results Mean
Results show the absolute count of CD19+ and CD23+ cells in your blood. Abnormal counts may indicate immune system disorders, infections, or other underlying health issues. Your provider will interpret results in the context of your overall health and symptoms.
Common Conditions Monitored
This test is often used to diagnose or monitor chronic lymphocytic leukemia (CLL), autoimmune diseases, or other immune-related conditions. It helps track changes in B-cell populations over time, especially after treatment.
Reference range
CD19+ B-lymphocytes: 100-500 cells/μL (5-20% of total lymphocytes); CD19+CD23+ subset represents approximately 60-80% of total CD19+ B-cells in healthy adults. Reference ranges vary by laboratory and population; interpret in conjunction with complete lymphocyte subset panel.N/A
No special preparation required. Patient should be well-hydrated. Recent corticosteroid therapy, chemotherapy, or immunosuppressive medications should be noted as they may affect lymphocyte subset counts.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormally high or low counts of CD19+ and CD23+ cells can signal immune dysfunction. For example, elevated counts might suggest CLL or other lymphoproliferative disorders, while very low counts could indicate immune suppression or certain infections. Always discuss results with your healthcare provider for personalized insights.
Short name
CD19/CD23 B-Cell Count
Frequently asked questions
What does a normal range mean for this test?
How often will I need this test?
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