Immunoglobulin G (IgG) Subclass 2 (Serum) by Electrophoresis
This test measures the amount of a specific type of antibody (IgG2) in your blood, which helps identify variations in your immune response.
["IgG2 antibodies play a role in fighting certain infections and diseases; levels can be checked for immune function or diagnostic purposes."]
Key facts at a glance
- LOINC
- 29617-8
- Short code
- CD23
- Synonyms
- CD23 Ag Tiss Ql ImStn
- Category
- chemistry
- Sample
- serum
- Container
- 10% neutral buffered formalin (NBF) container for tissue fixation; paraffin block or unstained slides for referral testing
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immune-stain
- CPT
- 88342
- SNOMED
- 37048007
- Specimen volume
- Adequate tissue biopsy or excision specimen; minimum 4 unstained paraffin sections (3-4 micron thick) on positively charged slides for optimal staining
- Stability
- Formalin-fixed paraffin-embedded (FFPE) tissue blocks: indefinite stability at room temperature. Unstained slides: stable for 1 year at room temperature. Fresh tissue should be fixed in 10% NBF for 6-72 hours prior to processing.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What Does This Test Measure?
IgG2 is one of five subclasses of Immunoglobulin G (IgG), a type of antibody produced by your immune system. This subclass is particularly important for responding to certain bacteria and some vaccines. The test measures its concentration in your serum to assess immune function or identify potential deficiencies.
Why Might You Need This Test?
Doctors may order this test if you have symptoms of a weakened immune system, recurrent infections, or if you’re being evaluated for conditions like common variable immunodeficiency (CVID) or certain autoimmune diseases. It can also help monitor immune responses after vaccination.
Sample Collection and Preparation
A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum, which is then analyzed using electrophoresis—a method that separates proteins based on size and charge.
What to Expect Before the Test
No special preparation is needed, but inform your healthcare provider about any medications you’re taking, as some may affect blood test results. Avoid strenuous activity or eating heavy meals before the draw if instructed.
Reference range
Reported as Positive or Negative for CD23 antigen expression. Positive staining typically shows membranous pattern in germinal center B-cells, follicular dendritic cells, and certain B-cell lymphomas. Interpretation requires pathologist review with appropriate positive and negative controls.N/A
No special patient preparation is required. Fasting is not necessary as the test is performed on tissue specimens, not serum. Tissue samples should be properly fixed and processed according to histopathology protocols.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG2 Subclass
Frequently asked questions
IgG2 deficiency can make you more susceptible to certain bacterial infections, such as sinusitis, pneumonia, or ear infections. Low levels may also be linked to autoimmune disorders or poor vaccine responses. High levels could indicate chronic inflammation or certain immune-related conditions.
Results are usually available within 1 to 3 business days, depending on your lab’s processing schedule. Your healthcare provider will discuss the findings with you during your follow-up visit.
While diet and supplements may influence overall immune function, IgG2 levels are primarily determined by your body’s natural immune response. Your doctor will consider other factors when interpreting results.
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