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B-cell Immunoglobulin G (IgG) Quantification in Peripheral Blood Cells

Published: August 9, 2026Updated: August 15, 2026

This test measures the amount of Immunoglobulin G (IgG), a type of antibody, specifically in B cells found in your blood. IgG is important for fighting infections and is a key part of your immune system.

Quick summary

["IgG levels in B cells can help diagnose or monitor certain immune-related conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
49842-8
Short code
CD19IGA
Synonyms
CD19+IgA+ cells NFr Spec
Category
chemistry
Sample
serum
Container
Heparinized (sodium or lithium heparin) or EDTA anticoagulant tube for whole blood flow cytometry; sterile collection tube for other specimen types
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Flow cytometry using fluorescein-labeled monoclonal antibodies against CD19 surface marker and intracellular IgA staining
CPT
86356
SNOMED
122575007
Specimen volume
3-5 mL whole blood for adults; 1-2 mL for pediatric patients
Stability
Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Do not refrigerate or freeze whole blood specimens intended for flow cytometric immunophenotyping, as this may affect cell viability and marker expression.
Hemolysis max
50
Lipemia max
100
Icterus max
50
TAT
24–72 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms of an immune disorder, such as frequent infections, unexplained fatigue, or if you’re being evaluated for conditions like chronic lymphocytic leukemia (CLL), autoimmune diseases, or immune deficiencies. It may also be used to monitor treatment responses in certain cancers or immune disorders.

What to Expect Before the Test

No special preparation is typically needed. You may have a small needle inserted into a vein in your arm to draw a blood sample. This is usually done in a clinic or hospital setting and takes about 15 minutes. If you’re on blood thinners or have a history of bleeding issues, let your provider know.

What the Test Results Mean

Results are compared to what’s expected in healthy individuals. Abnormally high or low levels of IgG in B cells might suggest an immune system issue, but results alone don’t diagnose a condition. Your provider will consider your symptoms, medical history, and other test results for a full evaluation.

Common Conditions Monitored or Diagnosed

This test can help identify or track conditions such as B-cell lymphomas, autoimmune diseases (like lupus or rheumatoid arthritis), or immune system disorders. It may also be used in research or specialized clinical settings to study immune cell function.

Reference range

Reference values for CD19+IgA+ B-lymphocytes are laboratory-specific; results are typically reported as percentage of total B-cells or absolute count per microliter. Consult laboratory-specific reference intervals.N/A

Specimen: serum

No special patient preparation is required. Avoid recent immunomodulatory therapy if possible, as it may affect results. Inform the laboratory of any current immunosuppressive or immunostimulant medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG in B Cells

Frequently asked questions

How is this test used in clinical practice?
This test is primarily used to assess the immune profile of B cells, particularly in diagnosing or monitoring conditions where IgG levels in these cells are relevant. It’s often part of a broader evaluation, especially in oncology, hematology, or immunology. For example, it may be used to evaluate the presence of malignant B cells in chronic lymphocytic leukemia or to monitor immune responses in autoimmune diseases.
What does it mean if my IgG levels in B cells are different from what’s expected?
Different from expected IgG levels in B cells could indicate an immune disorder, infection, or response to treatment. High levels might suggest overactive immune activity, while low levels could point to immune suppression. Your provider will discuss these findings with you and may recommend further testing or adjustments to your treatment plan.
Can I fast before this test?
No fasting is required for this blood test. However, always follow your healthcare provider’s instructions, as some tests may have specific guidelines depending on the reason for the 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 15, 2026. · Read our editorial policy