Immunoglobulin G (IgG) Subclass 2 Quantification (Serum)
This test measures the amount of Immunoglobulin G (IgG) subclass 2 in your blood, a type of antibody that helps fight certain infections.
["IgG2 antibodies play a key role in protecting against bacteria and some viruses."]
Key facts at a glance
- LOINC
- 107005-1
- Short code
- T. pallidum Ab.IgG 257 Ser Ql IB
- Synonyms
- T. pallidum Ab.IgG 257 Ser Ql IB
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ib
- CPT
- 82784
- 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
Why This Test Might Be Ordered
Your doctor may recommend this test if you have symptoms of a weakened immune system, recurrent infections, or if you’re being treated for conditions like asthma, allergies, or autoimmune diseases. It can also be part of evaluating why certain vaccines may not work as expected in some people.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood. The process usually takes a few minutes, and you can resume normal activities afterward.
What the Results Mean
Lower-than-expected IgG2 levels may indicate an immune deficiency or a condition that affects antibody production. Higher-than-expected levels might be seen in certain chronic infections or autoimmune disorders, but this is less common for IgG2 specifically.
Common Conditions Linked to IgG2 Levels
IgG2 deficiencies are rare but can be associated with increased susceptibility to bacterial infections, particularly those caused by encapsulated bacteria (like pneumococcus). Some people with IgG2 deficiencies may also have trouble responding to certain vaccines.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgG2 levels are important for diagnosing or monitoring conditions that affect antibody function, such as primary immunodeficiency diseases. They can also help guide treatment decisions for immune-related conditions, though they’re not the only factor considered.
Short name
IgG2 Level
Frequently asked questions
What causes IgG2 levels to be low?
How often should I get this test?
Can IgG2 levels change over time?
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