Immunoglobulins Panel (Serum)
It measures your main antibody levels (IgG, IgA, IgM) to assess immune patterns; order through Vitals Vault with Quest labs and PocketMD support.
This panel bundles multiple biomarker tests in one order—your report explains how results fit together.
An immunoglobulins panel (serum) measures the main antibody classes circulating in your blood—IgG, IgA, and IgM. These proteins are a big part of how your immune system recognizes germs and responds to infections.
This test is often used when you have a pattern that needs an explanation, such as frequent sinus or lung infections, unusually severe infections, chronic diarrhea, or poor response to vaccines. It can also help clarify whether inflammation or certain immune conditions may be contributing to your symptoms.
Your numbers do not diagnose a specific condition on their own. They are best interpreted alongside your history, medications, and sometimes follow-up testing that your clinician chooses based on the pattern.
Do I need a Immunoglobulins Panel Serum test?
You might consider an immunoglobulins panel if you keep getting infections that feel “out of proportion,” such as repeated sinusitis, ear infections, bronchitis, pneumonia, or infections that take longer than expected to clear. It can also be useful if you have chronic gastrointestinal symptoms (like persistent diarrhea) or unexplained weight loss where immune causes are on the table.
This test is also commonly ordered when a clinician is evaluating possible antibody deficiency (a humoral immune problem), monitoring known immune disorders, or checking whether immune-suppressing medications could be affecting your antibody levels. If you have a history of autoimmune disease, chronic inflammatory conditions, or certain blood disorders, immunoglobulin patterns can add helpful context.
If you are deciding whether treatments like immunoglobulin replacement (IVIG/SCIG) are appropriate, that decision is clinician-led and usually requires more than a single panel. The immunoglobulins panel is a starting point that can support a careful, stepwise evaluation rather than self-diagnosis.
This is a serum blood test typically performed in a CLIA-certified laboratory; results should be interpreted with your clinical context and are not a standalone diagnosis.
Lab testing
Ready to order an Immunoglobulins Panel (Serum) and test at a Quest location?
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
If you want to check your antibody levels without waiting for a referral, you can order an Immunoglobulins Panel (Serum) through Vitals Vault and complete the blood draw at a participating Quest location.
Once your results are in, PocketMD can help you translate the pattern into plain language—what a low IgG versus a high IgA often suggests, what follow-up questions matter, and which companion labs are commonly paired with immunoglobulins when recurrent infections or immune dysregulation is a concern.
Vitals Vault is also useful when you and your clinician plan longitudinal monitoring. Repeating immunoglobulins over time can help distinguish a temporary dip (for example after an illness or medication change) from a persistent pattern that deserves a deeper workup.
- Order online and draw at Quest locations
- PocketMD guidance for next-step questions and context
- Designed for trending results over time when monitoring is planned
Key benefits of Immunoglobulins Panel Serum testing
- Helps explain patterns of recurrent or unusually severe infections by checking core antibody classes (IgG, IgA, IgM).
- Flags possible antibody deficiency patterns that may warrant vaccine-response testing or immunology referral.
- Adds context when symptoms overlap with allergy, asthma, chronic sinus disease, or frequent “bronchitis” episodes.
- Supports monitoring when medications or conditions could suppress antibody production over time.
- Helps differentiate broad immune activation (polyclonal elevation) from patterns that may need targeted follow-up testing.
- Provides a baseline before and during clinician-directed therapies that affect the immune system.
- Makes it easier to track immune trends and discuss results with PocketMD in a structured, symptom-linked way.
What is Immunoglobulins Panel Serum?
Immunoglobulins are antibodies—proteins made by B cells (a type of white blood cell) that help your body recognize and neutralize bacteria, viruses, and other foreign substances. A serum immunoglobulins panel measures the concentration of the three major antibody classes in blood: IgG, IgA, and IgM.
Each class has a different job. IgG is the most abundant antibody in your bloodstream and is important for long-term protection and “memory” responses. IgA is concentrated in mucosal surfaces like the nose, lungs, and gut, where many infections start. IgM is often an early responder, rising during new immune challenges.
The panel does not directly measure how well your antibodies function. If your levels are low or your infection history is concerning, clinicians often add tests that evaluate antibody responses to vaccines (for example, pneumococcal antibody titers) or look for protein abnormalities (for example, serum protein electrophoresis) depending on the pattern.
IgG (Immunoglobulin G)
IgG supports longer-term immunity and helps your body clear many common bacteria and viruses. Persistently low IgG can be associated with recurrent respiratory infections, poor vaccine responses, or certain immune deficiencies. High IgG is more often linked to chronic inflammation, infection, or autoimmune activity than to “stronger immunity.”
IgA (Immunoglobulin A)
IgA helps protect mucosal surfaces, including the sinuses, airways, and gastrointestinal tract. Low IgA can be associated with recurrent sinus or GI infections and may coexist with allergies or autoimmune conditions. High IgA can occur with chronic inflammation and some liver or immune-related conditions, and it sometimes prompts follow-up if the elevation is marked or persistent.
IgM (Immunoglobulin M)
IgM is often the first antibody type produced in response to a new infection. Low IgM can be seen in some immune deficiencies or with immune-suppressing therapies. High IgM can reflect recent infection or immune activation, but persistent elevations may require clinician-directed evaluation in the right context.
What do my Immunoglobulins Panel Serum results mean?
Low immunoglobulin levels
Low IgG, IgA, and/or IgM can suggest reduced antibody production or increased loss of antibodies from the body. In real life, the meaning depends on which immunoglobulin is low and whether you also have a history of recurrent infections, poor vaccine responses, or chronic lung or sinus disease. Some low results are secondary (for example, related to certain medications, kidney or gut protein loss, or blood cancers), while others point toward primary immune deficiency patterns. If your result is low, the next step is usually to confirm persistence and consider functional antibody testing and a clinician-guided workup.
In-range (typical) immunoglobulin levels
In-range IgG, IgA, and IgM generally means your circulating antibody quantities are typical for the lab’s reference population. This is reassuring, but it does not completely rule out immune problems, because antibody function and vaccine response can still be impaired in some cases. If you have frequent infections despite normal levels, clinicians may look at specific antibody titers, IgG subclasses, lymphocyte subsets, or non-immune explanations such as anatomy, allergies, or exposure risk. Your pattern of symptoms matters as much as the numbers.
High immunoglobulin levels
High immunoglobulins often reflect immune activation rather than “extra protection.” Polyclonal elevations (multiple immunoglobulins elevated) can occur with chronic infections, inflammatory or autoimmune conditions, and some liver diseases. A more isolated or pronounced elevation may prompt follow-up to rule out a monoclonal process, especially if there are symptoms like unexplained anemia, bone pain, weight loss, or abnormal total protein. Your clinician may pair this result with tests like serum protein electrophoresis (SPEP) and immunofixation depending on the pattern.
Factors that influence immunoglobulins
Recent infections, vaccinations, and chronic inflammation can raise immunoglobulin levels temporarily or persistently. Immune-suppressing drugs (including some biologics and chemotherapy), long-term steroid use, and certain anti-seizure medications can lower levels in some people. Protein loss through the kidneys (nephrotic syndrome) or gastrointestinal tract can reduce measured immunoglobulins even if production is normal. Age, pregnancy status, hydration, and lab-to-lab reference ranges can also shift what “normal” looks like, so trending and context are important.
What’s included
- Immunoglobulin A
- Immunoglobulin G
- Immunoglobulin M
Frequently Asked Questions
Do I need to fast for an immunoglobulins panel (IgG, IgA, IgM)?
Fasting is not usually required for serum IgG, IgA, and IgM. If your blood draw includes other tests that do require fasting (such as lipids), follow the instructions for the full order.
What is the difference between an immunoglobulins panel and IgG subclasses?
An immunoglobulins panel measures total IgG, IgA, and IgM. IgG subclasses break IgG into subtypes (IgG1–IgG4). Subclass testing is more specialized and is typically considered when total IgG is normal but infection history suggests an antibody problem, or when a clinician is evaluating specific immune patterns.
Can normal IgG, IgA, and IgM still mean I have immune problems?
Yes. Quantity is only one part of immunity. Some people have normal immunoglobulin levels but reduced antibody function, which can show up as poor responses to vaccines or low pathogen-specific antibody titers. Your infection history and response to vaccines often guide next steps.
What causes low IgG?
Low IgG can be due to primary immune deficiency, medication effects (including some immune-targeting therapies), protein loss from kidney or gut conditions, or certain blood and lymph disorders. A single low result is often rechecked, and clinicians may add tests that assess vaccine responses and overall protein patterns.
What causes high immunoglobulins?
High immunoglobulins commonly reflect chronic immune stimulation, such as ongoing inflammation, infection, autoimmune activity, or liver disease. Depending on which immunoglobulin is elevated and how high it is, a clinician may order follow-up testing to distinguish polyclonal elevation from a monoclonal protein pattern.
Is this test used to decide on IVIG?
It can contribute, but IVIG decisions are not based on this panel alone. Clinicians typically consider your infection history, vaccine antibody responses, other immune tests, and sometimes imaging or specialist evaluation. The immunoglobulins panel is often an early data point in that larger decision process.