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B-cell Lymphocyte Subset Count: CD19+ and CD23+ Cells in Peripheral Blood

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

This test measures the number of specific immune cells (B-cells) marked by CD19 and CD23 markers in your blood. These markers help identify mature B-cells that play a role in immune response and antibody production.

Quick summary

["Understanding your B-cell counts can help assess immune function and diagnose conditions like chronic lymphocytic leukemia (CLL)."]

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

Key facts at a glance

LOINC
57399-8
Short code
CD19CD23
Synonyms
CD19+CD23+ Cells NFr Fld
Category
chemistry
Sample
serum
Container
Sterile body fluid collection container; anticoagulated specimen tube (EDTA or heparin) for blood-derived fluids to preserve cell viability
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Flow cytometry using fluorescently labeled monoclonal antibodies (CD19 and CD23) with immunophenotyping analysis
CPT
88184 (Flow cytometry, cell surface, cytoplasmic, or nuclear marker, technical component only; first marker); additional markers reported with 88185
SNOMED
1428001000000100 | CD19+CD23+ cells measurement (procedure)
Specimen volume
Minimum 1-2 mL of body fluid; larger volumes preferred for cell concentration when cell counts are low
Stability
Specimen should be processed within 4-6 hours of collection for optimal cell viability. Store at room temperature (18-25°C); do not refrigerate as this may cause cell clumping and death. If delayed, fixative or preservative may be required per laboratory protocol.
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 signs of an immune disorder, such as frequent infections, fatigue, or unexplained lymph node swelling. It may also be used to monitor conditions like chronic lymphocytic leukemia (CLL) or other B-cell-related diseases. Sometimes, it’s part of a broader evaluation for autoimmune diseases or immune deficiencies.

What to Expect Before the Test

No special preparation is usually needed. You’ll have a small needle inserted into a vein (typically in your arm) to draw a blood sample. This process is quick and often done in a clinic or lab. If you’re on blood-thinning medication, let your provider know before the test.

What the Test Results Mean

The test measures the absolute count of CD19+ and CD23+ cells in your blood. While specific reference ranges vary by lab, abnormal counts may suggest immune system issues, such as an overactive or underactive B-cell response. 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 conditions like chronic lymphocytic leukemia (CLL), where B-cells proliferate abnormally. It may also help assess autoimmune diseases (e.g., rheumatoid arthritis) or immune deficiencies (e.g., hypogammaglobulinemia), where B-cell function is impaired.

Reference range

Reference values vary by laboratory and specimen type; results expressed as percentage of total lymphocytes or absolute count per microliter. CD19+CD23+ cells typically constitute a subset of B-lymphocytes and are evaluated in clinical context.N/A

Specimen: serum

No special patient preparation required. Inform physician of recent immunosuppressive therapy, chemotherapy, or corticosteroid use as these may affect lymphocyte subset distribution.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated CD19+ and CD23+ cell counts may indicate conditions like CLL, where B-cells are overproduced. Low counts could suggest immune system dysfunction, such as in certain autoimmune diseases or after treatments that suppress the immune response. Your provider will use these results alongside other tests and symptoms to guide diagnosis and treatment.

Short name

CD19/CD23 B-Cell Count

Frequently asked questions

How long does it take to get my test results?
Test results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will contact you directly with the results, so keep their contact information handy.
What does it mean if my B-cell count is higher or lower than expected?
Higher-than-normal counts may signal conditions like CLL or other B-cell disorders, while lower counts could indicate immune deficiencies or treatments affecting B-cell function. Only your provider can interpret these results in relation to your health and symptoms.
Can I eat or drink before this test?
You can eat and drink normally before this test unless instructed otherwise by your provider. No special fasting is required for this blood draw.
  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