Immunoglobulin G Subclass 2 Concentration (Serum)
This test measures the amount of Immunoglobulin G (IgG) subclass 2 in your blood serum. IgG is part of your immune system and helps fight infections.
["IgG2 helps protect against certain bacteria and viruses, and its levels can indicate immune function or response to treatments."]
Key facts at a glance
- LOINC
- 56688-5
- Short code
- IgD Ser-aCnc
- Synonyms
- IgD Ser-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Is IgG2 Used For?
IgG2 is one of five subclasses of Immunoglobulin G antibodies. Each subclass plays a role in immunity, but IgG2 is particularly important for defending against some bacterial infections. Your doctor may order this test if they suspect an immune disorder, such as a deficiency in IgG2, or to monitor treatment effectiveness in conditions like recurrent infections.
Why Might Your Doctor Order This Test?
A doctor might recommend this test if you have frequent or severe infections, particularly those caused by bacteria like *Streptococcus* or *Pneumococcus*. It could also be used in research or clinical settings to study immune responses or evaluate conditions like common variable immunodeficiency (CVID).
What Does a Result Mean?
Results are not typically provided as a single reference range since IgG2 levels can vary widely among individuals. Instead, your doctor will compare your result to your baseline or to known standards for your age and health status. Very low levels may suggest an IgG2 deficiency, while very high levels could indicate an overactive immune response or certain autoimmune conditions.
How Is This Test Done?
A blood sample is drawn from a vein in your arm. The serum (liquid part of blood without blood cells) is then tested using an immunoassay method to measure IgG2 concentration. This process is quick and usually requires no special preparation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG2 plays a key role in protecting against certain bacterial infections, and its levels can help identify immune system issues. Low IgG2 levels may indicate a need for further evaluation of immune function, while abnormal high levels could warrant investigation into underlying conditions like autoimmune diseases.
Short name
IgG2 Level
Frequently asked questions
How often should I get this test?
What do I need to do before the test?
Will the test hurt?
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