Serum Immunoassay for Immunoglobulin G (IgG) Subclass 1 (IgG1)
This test measures the amount of a specific type of antibody (IgG1) in your blood, which plays a key role in fighting infections and helping the immune system respond to certain diseases.
["IgG1 helps identify immune responses and may be checked if you have symptoms of immune-related conditions or need monitoring for certain infections or treatments."]
Key facts at a glance
- LOINC
- 96468-4
- Short code
- IP3R 1 IgG CSF Ql CBA IFA
- Synonyms
- IP3R 1 IgG CSF Ql CBA IFA
- Category
- coagulation
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- cba-ifa
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
IgG1 is one of four subclasses of Immunoglobulin G (IgG), a type of antibody produced by your immune system. IgG1 is particularly important for responding to viruses, bacteria, and toxins. This test specifically measures the concentration of IgG1 in your serum, which can help doctors assess immune function, diagnose certain conditions, or monitor treatment responses.
Why Might You Need This Test?
Your doctor may order an IgG1 test if you have symptoms like frequent infections, autoimmune diseases (such as lupus or rheumatoid arthritis), or if you’re receiving treatments that affect your immune system. It can also be used to check for immune deficiencies or to monitor immune responses to vaccines or infections.
Sample Collection and Preparation
A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate the serum (the liquid part without clotting factors), which is sent to the lab for testing. This test does not require fasting or special preparation beyond standard blood draw procedures.
What to Expect Before the Test
No special preparation is needed for this test. However, if you’re on certain medications that affect blood clotting or immune function, your doctor may advise you to stop them temporarily or discuss alternatives.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low IgG1 levels may suggest an immune deficiency, chronic infections, or certain autoimmune diseases. High IgG1 levels can sometimes indicate overactive immune responses, such as in allergic reactions, certain cancers, or chronic infections. Doctors use these results to guide treatment plans, such as adjusting medications or identifying underlying conditions that need further investigation.
Short name
IgG1 Level
Frequently asked questions
What Are Normal Results?
How Long Does It Take to Get Results?
Can Diet or Medications Affect This Test?
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