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B-cell CD19 and CD38 Immunophenotyping in Peripheral Blood

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

This test measures the presence and proportion of B-cell markers (CD19 and CD38) in your blood to help assess immune cell characteristics, often used in diagnosing or monitoring conditions like lymphoma or leukemia.

Quick summary

["This blood test helps doctors evaluate B-cell populations for potential cancer or immune disorders."]

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

Key facts at a glance

LOINC
89343-8
Short code
CD19CD38IgM
Synonyms
CD19+CD38+IgM- cells # Bld
Category
chemistry
Sample
whole-blood
Container
EDTA (lavender-top) or heparinized (green-top) whole blood tube; acid-citrate-dextrose (ACD) tubes are also acceptable for flow cytometry
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Flow cytometry (multi-parameter immunophenotyping) using CD19, CD38, and surface IgM markers
CPT
86356 (each monoclonal antibody marker; may be reported as 86356x3 for CD19, CD38, and IgM)
SNOMED
444571005 (Measurement of lymphocyte subset) / 395145001 (B-lymphocyte count)
Specimen volume
3-5 mL of whole blood (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 as cold can cause loss of surface markers. For delays beyond 24 hours, consult laboratory-specific stability guidelines.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–48 hours
Order
routine

What This Test Measures

The test identifies specific proteins (CD19 and CD38) on B-cells, which are a type of white blood cell involved in immune responses. CD19 is a marker found on nearly all mature B-cells, while CD38 is often expressed in certain B-cell malignancies or activated immune cells.

Why It’s Done

Your doctor may order this test if you have symptoms of blood disorders (e.g., fatigue, unexplained weight loss), a suspected blood cancer (like lymphoma or chronic lymphocytic leukemia), or if you’re undergoing treatment for an immune-related condition.

Sample Collection and Preparation

A small blood sample is drawn from a vein, typically in your arm. The sample is processed to analyze the specific markers on B-cells using advanced flow cytometry technology.

What to Expect Before or After

No special preparation is needed, but inform your doctor about any medications or recent illnesses that might affect results. After the draw, you may experience mild bruising or soreness at the site, but this usually resolves quickly.

Reference range

Reference ranges for CD19+CD38+IgM- cells are laboratory-specific and vary by age and population; values are interpreted in conjunction with other B-cell subset markers and clinical context. Consult the performing laboratory's reference interval report for specific numeric ranges.N/A

Specimen: whole-blood

No special patient preparation is required. Inform the laboratory of any recent immunosuppressive therapy, chemotherapy, or monoclonal antibody treatment (e.g., rituximab, anti-CD38 therapy) as these may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal levels of CD19/CD38 markers can indicate conditions such as B-cell lymphoproliferative disorders (e.g., non-Hodgkin lymphoma), chronic infections, or autoimmune diseases. These markers help guide treatment decisions, such as targeted therapies or monitoring disease progression.

Short name

CD19/CD38 Flow Cytometry

Frequently asked questions

Will this test show if I have cancer?
This test helps identify abnormal B-cell populations that may suggest a blood cancer or immune disorder, but it’s not a definitive diagnosis on its own. Results will be reviewed by a hematologist or pathologist alongside other tests and clinical findings.
How long will I need to wait for results?
Results are typically available within 2–5 business days, depending on lab processing times. Your doctor will contact you with the findings once they’re ready.
Can I eat or drink before this test?
No special diet is required, but avoid caffeine or alcohol before the blood draw if your doctor recommends it. Follow any specific instructions they provide for your test.
  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