Immunoglobulin G (IgG) Subclass 1 (Serum) Concentration
This test measures the amount of Immunoglobulin G subclass 1 (IgG1), a type of antibody in your blood. IgG1 helps protect your body from infections and plays a role in immune responses.
["IgG1 helps fight infections and supports immune function; levels may indicate immune health or response to treatments."]
Key facts at a glance
- LOINC
- 10489-3
- Short code
- IgA HC Ag Tiss Ql ImStn
- Synonyms
- IgA HC Ag Tiss Ql ImStn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immune-stain
- 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 healthcare provider may order this test to evaluate your immune system, check for immune deficiencies, monitor treatment responses (like for autoimmune diseases or infections), or assess antibody production in conditions such as HIV, hepatitis, or certain cancers. It may also be used in research or specialized diagnostic scenarios.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners or have a history of bleeding issues, let your provider know. Avoid alcohol for 24 hours before testing if instructed.
What the Results Mean
Results are compared to a general reference range for healthy adults. Low levels might suggest immune problems, while high levels could indicate overactive immune responses or certain medical conditions. Your provider will interpret results in the context of your overall health.
Common Conditions Affecting IgG1 Levels
IgG1 levels can be lower in people with immune disorders (e.g., HIV/AIDS, certain autoimmune diseases), chronic infections, or conditions affecting antibody production. High levels may be seen in chronic infections, some cancers, or inflammatory diseases. Always discuss results with your doctor.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
IgG1 Level
Frequently asked questions
How long does it take to get my IgG1 test results?
Can I eat or drink before this test?
Is there anything I should avoid before the blood draw?
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