Serum Immunoglobulin G (IgG) with Subtyping (A, B, C, D, E)
This test measures different types (subtypes) of Immunoglobulin G (IgG), a key antibody in your immune system. IgG subtypes help assess immune function, response to infections, or underlying conditions like immunodeficiency.
["IgG subtypes can indicate how well your immune system produces antibodies and whether certain types are low or high, which may relate to health risks or treatment needs."]
Key facts at a glance
- LOINC
- 101462-0
- Short code
- Septin-5 IgG CSF Ql CBA IFA
- Synonyms
- Septin-5 IgG CSF Ql CBA IFA
- Category
- coagulation
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- cba-ifa
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may order this test if you have symptoms of a weakened immune system, such as frequent infections, unexplained fatigue, or if you’re being treated for conditions like lupus, rheumatoid arthritis, or certain autoimmune diseases. It can also be used to monitor immune responses to vaccines or treatments like chemotherapy.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. If you’re on blood thinners, let your provider know before the test.
What the Test Results Mean
Results show the levels of IgG subtypes (A, B, C, D, E) compared to what’s typical for your age and health. Lower levels may suggest immune deficiencies, while higher levels could be linked to chronic infections, certain cancers, or autoimmune diseases. Your provider will interpret these results in the context of your overall health.
Common Conditions Linked to IgG Subtype Results
Abnormal IgG subtypes can signal conditions like common variable immunodeficiency (CVID), HIV/AIDS, or other immune disorders. They may also help diagnose or monitor diseases like lupus, where IgG antibodies can be elevated or altered.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG Subtyping
Frequently asked questions
What does a low IgG subtype mean?
How long does it take to get IgG subtype results?
Can IgG subtypes 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