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Flow Cytometry Analysis of CD19 and CD27 Markers on B-Lymphocytes (Peripheral Blood)

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

This test measures specific protein markers (CD19 and CD27) on white blood cells called B-cells, which are part of your immune system. It helps assess their maturity and presence in your blood.

Quick summary

["This test helps evaluate immune health, especially in diagnosing or monitoring conditions like B-cell lymphoma or immune deficiencies."]

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

Key facts at a glance

LOINC
43273-2
Short code
CD19CD27IgD
Synonyms
CD19+CD27+IgD+ Cells NFr Bld/T
Category
chemistry
Sample
whole-blood
Container
Heparinized (sodium or lithium heparin) or EDTA anticoagulated tube. ACD-A tubes are also acceptable. Use sterile, endotoxin-free tubes specifically validated for flow cytometry immunophenotyping.
Units
N/A
Ref low
5
Ref high
15
Fasting
false
Population
adult
Sex
all
Age range
0–99 years
Method
Flow cytometry using fluorescently-labeled monoclonal antibodies against CD19 (pan-B cell marker), CD27 (memory B cell marker), and IgD (naive B cell marker), followed by multiparameter analysis to identify CD19+CD27+IgD+ non-switched memory B cells. Whole blood is stained with fluorochrome-conjugated antibodies, red blood cells are lysed, and cells are acquired on a flow cytometer.
CPT
86356 (Mononuclear cell antigen enumeration by flow cytometry; each additional marker - commonly applied for multi-marker panels)
SNOMED
395125005 |Measurement of B lymphocyte subset (procedure)|; 269476004 |B lymphocytes - CD19 positive cells measurement (procedure)|
Specimen volume
3-5 mL of whole blood for adults; minimum 1 mL for pediatric patients. Peripheral blood samples should be collected in anticoagulant tubes and maintained at room temperature (18-25°C).
Stability
Specimen should be processed within 24-30 hours of collection when stored at room temperature (18-25°C). Do not refrigerate or freeze whole blood samples as this may affect cell viability and surface marker expression. Samples older than 48 hours are generally considered unacceptable.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
24–72 hours
Order
routine

Why This Test Is Done

Doctors may order this test if you have symptoms like fatigue, weight loss, or swollen lymph nodes, or if you’re being evaluated for a blood-related disorder. It can also be used to monitor treatment progress in certain cancers or immune conditions.

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), and blood will be drawn into a tube. The process takes about 5 minutes.

What the Test Results Mean

The test looks at the proportion and activity of CD19/CD27-positive B-cells. Abnormal results may indicate immune system issues, infections, or certain cancers. Your doctor will discuss findings with you based on your medical history.

Common Conditions Monitored

This test is often used to diagnose or track conditions like chronic lymphocytic leukemia (CLL), non-Hodgkin lymphoma, or autoimmune diseases affecting B-cells.

Reference range

Reference ranges vary by laboratory and age. In healthy adults, CD19+CD27+IgD+ non-switched memory B cells typically represent approximately 5-15% of total CD19+ B lymphocytes. Absolute counts are generally 8-50 cells/μL. Pediatric values differ; consult age-specific reference intervals provided by the performing laboratory.N/A

Specimen: whole-blood

No special patient preparation is required. Fasting is not necessary. Patients should inform the laboratory of any recent immunomodulatory therapy (e.g., rituximab, corticosteroids, chemotherapy) or immunosuppressive medications that may affect lymphocyte subsets. Avoid strenuous exercise immediately before collection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CD19/CD27 B-Cell Immunophenotyping

Frequently asked questions

What does a ‘positive’ or ‘abnormal’ result mean?
A ‘positive’ or abnormal result refers to an unusual number or behavior of CD19/CD27 markers on B-cells. This could mean your immune system is overactive (e.g., lymphoma), underactive (e.g., immunodeficiency), or that cancer cells are present. Your doctor will interpret results in the context of your symptoms and medical history.
How often will I need this test?
Frequency depends on your condition. Some patients need it once at diagnosis, others regularly during treatment (e.g., every few months) to monitor changes. Your doctor will outline a schedule based on your care plan.
Can I eat or drink before this test?
No restrictions apply. You can eat, drink water, and take your usual medications as usual. The test only requires a small blood draw and no fasting is needed.
  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