Immunoglobulin Blood Test (IgG, IgA, IgM, IgE): How to Read the Whole Panel

Your report shows three or four lines that all start with "Ig," and one or two of them carry a flag. Immunoglobulins are the antibodies made by plasma cells, a type of white blood cell. Measuring them together, often called quantitative immunoglobulins, gives a picture of how well your body produces antibodies^[1]. This guide reads the panel as a whole: what each line means, which combinations matter and what usually comes next. Each antibody also has its own detailed page, starting with our guide to IgG blood test results, the largest of the four.

What does an immunoglobulin blood test report look like?

Most US labs report IgG, IgA and IgM in milligrams per deciliter (mg/dL). Total IgE is ordered separately or added when an allergy is suspected, and is reported in kU/L or IU/mL. The example below shows a pattern that often leads to a follow-up visit.

Fictitious example of an immunoglobulin panel (United States format)

Test	Result	Reference range	Flag
Immunoglobulin G (IgG), serum	540 mg/dL	700-1600 mg/dL	L
Immunoglobulin A (IgA), serum	62 mg/dL	103-501 mg/dL	L
Immunoglobulin M (IgM), serum	85 mg/dL	40-230 mg/dL
Immunoglobulin E (IgE), total	45 kU/L	214 kU/L or less

1. IgG, flagged L: the main antibody in the blood, the one that gives long-term protection. A level below the range is the key finding here.
2. IgA, flagged L: the antibody that guards the lining of the airways and gut. Low together with IgG, it makes an antibody deficiency more likely than a lab fluke.
3. IgM, normal: the first antibody made against a new germ. A normal IgM does not cancel out the other two results.
4. Total IgE, normal: linked to allergy and parasites. It is not part of every panel and does not reflect your overall defenses.
5. Reference ranges: the IgG, IgA and IgM ranges are typical adult values from MedlinePlus^[2]; the IgE limit comes from one reference lab^[3]. Children have different, age-based ranges, so always read your result against your own lab's range.

What do IgG, IgA, IgM and IgE each tell you?

The four antibodies do different jobs, so the same flag does not mean the same thing on each line. The table gives typical adult ranges and links to the full guide for each marker.

Immunoglobulin panel: role of each antibody, typical adult range and detailed guide

Antibody	Main role	Typical adult range	Full guide
IgG	Most abundant in blood; long-term protection after an infection or a vaccine	700-1600 mg/dL (7.0-16.0 g/L)[2]	IgG results
IgA	Protects the airways, gut, saliva, tears and breast milk[1]	103-501 mg/dL (1.0-5.0 g/L)[2]	IgA blood test
IgM	First antibody against a new germ	40-230 mg/dL (0.40-2.3 g/L)[2]	IgM results
Total IgE	Allergy and defense against parasites	214 kU/L or less[3]	Total IgE test

To convert mg/dL to g/L, divide by 100 (540 mg/dL = 5.4 g/L). Some labs outside the United States report IgE in IU/mL; for total IgE, 1 IU/mL and 1 kU/L are used as the same value.

How do you read the combinations on an immunoglobulin panel?

Your clinician compares the levels with each other and with your symptoms. An immunoglobulin test alone cannot diagnose a disease, and an abnormal result often leads to more testing^[1].

Common immunoglobulin patterns and what they usually suggest

Pattern	What it often means	Usual next step
All values within range	Normal antibody production for your age	Nothing, unless infections keep coming back
IgG low, with IgA and/or IgM low	Antibody deficiency (hypogammaglobulinemia), most often secondary to a medicine, a blood cancer or protein loss[4]; rarely an inborn disorder such as CVID[5]	Repeat test, search for a cause, vaccine response tests
IgA very low or absent, IgG and IgM normal	Selective IgA deficiency, the most common inborn immune deficiency, often without symptoms[6][7]	Note it in your file, especially before a transfusion
Several values high together (polyclonal rise)	An immune system that is working hard: chronic infection, autoimmune disease, hepatitis or cirrhosis[1]	Look for the cause; electrophoresis shows a broad band
One value very high, the others low	Possible monoclonal protein from a single family of plasma cells: MGUS, myeloma, lymphoma or Waldenström macroglobulinemia[1][9]	Serum protein electrophoresis and immunofixation
IgM high alone	Recent infection such as mononucleosis; less often lymphoma or Waldenström macroglobulinemia[2]	Recheck after the infection, more tests if it stays high
IgE high alone	Allergy, eczema, asthma or parasites	See the total IgE guide; allergy testing if needed

What causes low immunoglobulin levels?

Low antibodies make infections more frequent, especially repeated sinus, ear, chest or gut infections, or infections with the same germ again and again^[1]. Causes acquired during life are much more common than inborn ones^[4]:

• Common Medicines: immunosuppressive drugs and treatments that target B cells, the cells that become antibody factories^[4]. Never stop a treatment on your own.
• Common Blood cancers and their treatment: chronic lymphocytic leukemia and multiple myeloma often lower normal antibodies^[4].
• Possible Protein loss or poor intake: kidney disease, severe burns, malabsorption or malnutrition^[1]. A low total protein or albumin on the same report supports this.
• Possible Selective IgA deficiency: many people have no symptoms; others have more airway and gut infections, allergies or autoimmune problems^[6][7]. It also changes how celiac disease tests are read, as our IgA guide explains.
• Rare Common variable immunodeficiency (CVID): low IgG and IgA, sometimes IgM, with poor protection from vaccines; it affects about 1 in 25,000 to 1 in 50,000 people^[5].

When IgG is low, clinicians often add a complete blood count and a lymphocyte count, check kidney and gut protein loss, and measure your antibody response to past vaccines^[5]. People with complete IgA deficiency can make antibodies against IgA, which can cause severe reactions to blood products, so it should appear in their medical record^[6].

Polyclonal or monoclonal: what does high immunoglobulin mean?

A rise in antibodies can come in two very different shapes, and electrophoresis tells them apart^[8]:

• Common Polyclonal rise: many families of plasma cells make more antibodies at once. IgG, IgA and IgM rise together, and the gamma band of the electrophoresis is broad. Causes include chronic infection (for example HIV or hepatitis), cirrhosis, rheumatoid arthritis and lupus^[1][2].
• Possible Monoclonal rise: a single clone of plasma cells makes one identical antibody. Typically one immunoglobulin is high while the others are pushed down^[1][9]. Most often it is MGUS, a harmless-looking finding present in 3.2% of people aged 50 and older^[10], which needs regular follow-up.
• Rare Blood cancer: multiple myeloma, lymphoma or Waldenström macroglobulinemia, diagnosed with further tests and never from this panel alone^[1].

If a monoclonal protein is suspected, the next tests are usually a serum protein electrophoresis, an immunofixation that names the antibody type, and a kappa/lambda light chain test^[8][9]. Our page on gamma globulins explains the band where these antibodies appear.

How should you prepare for an immunoglobulin blood test?

It is a simple blood draw from a vein, and no special preparation is needed^[1]. If other tests on the same order require fasting, follow those instructions, as explained in our guide on fasting before a blood test. Before the draw, it helps to note:

• All your medicines, because some can change the results; do not stop any without advice^[1].
• Any infection in the past few weeks, which can raise IgM or IgG for a while^[2].
• How many infections you have had this year and which ones, since repeated infections are the main reason this test is ordered^[1].
• Any previous immunoglobulin results, so the trend can be compared.

Frequently asked questions

Is an immunoglobulin test the same as an antibody test for an infection?

No. This panel measures the total amount of each antibody class. A test for a specific infection, such as an IgG or IgM against a virus, looks only for the antibodies aimed at that germ, as in the TORCH panel in pregnancy.

Are immunoglobulin levels lower in children?

Yes. Babies rely partly on antibodies passed on by their mother and build their own levels over years, so labs use age-based ranges. For total IgE, for example, one reference lab uses 97 kU/L or less at 1 to 2 years and 307 kU/L or less at 4 to 6 years^[3].

Does an abnormal result always need treatment?

No. Abnormal immunoglobulin levels do not always mean a condition that needs treatment, and certain medicines can change the results^[1]. Treating the cause, for example a drug or a protein loss, can be enough; antibody replacement is reserved for selected people with a proven deficiency and frequent infections.

What is the difference between this panel and a protein electrophoresis?

The panel gives an exact amount for each antibody class. Electrophoresis shows the shape of all blood proteins, including the gamma band where antibodies sit, and can reveal a single narrow spike^[8]. The two are often ordered together.

Related tests and guides

• IgG blood testThe largest antibody, high or low, in depth.
• IgA blood testIgA deficiency and why it matters for celiac tests.
• IgM blood testThe first antibody against a new infection.
• Total IgEAllergy, ranges by age and high levels.
• Serum protein electrophoresisThe test that tells a broad rise from a spike.

References

1. MedlinePlus. Immunoglobulins blood test. National Library of Medicine. medlineplus.gov (accessed November 6, 2026)
2. MedlinePlus Medical Encyclopedia. Quantitative nephelometry (IgG, IgM, IgA). medlineplus.gov (accessed November 6, 2026)
3. ARUP Laboratories. Immunoglobulin E (test 0050345): reference intervals by age and turnaround. aruplab.com (accessed November 6, 2026)
4. Patel SY, Carbone J, Jolles S. The expanding field of secondary antibody deficiency: causes, diagnosis, and management. Front Immunol. 2019;10:33. doi:10.3389/fimmu.2019.00033 (accessed November 6, 2026)
5. MedlinePlus Genetics. Common variable immune deficiency. National Library of Medicine. medlineplus.gov (accessed November 6, 2026)
6. MedlinePlus Medical Encyclopedia. Selective deficiency of IgA. medlineplus.gov (accessed November 6, 2026)
7. Yel L. Selective IgA deficiency. J Clin Immunol. 2010;30(1):10-16. doi:10.1007/s10875-009-9357-x (accessed November 6, 2026)
8. O'Connell TX, Horita TJ, Kasravi B. Understanding and interpreting serum protein electrophoresis. Am Fam Physician. 2005;71(1):105-112. aafp.org (PubMed 15663032, accessed November 6, 2026)
9. American Cancer Society. Tests to find multiple myeloma. cancer.org (accessed November 6, 2026)
10. Kyle RA, Therneau TM, Rajkumar SV, et al. Prevalence of monoclonal gammopathy of undetermined significance. N Engl J Med. 2006;354(13):1362-1369. doi:10.1056/NEJMoa054494 (accessed November 6, 2026)
11. Medicare.gov. Diagnostic laboratory tests. Centers for Medicare & Medicaid Services. medicare.gov (accessed November 6, 2026)

This article is general health information. It does not replace a medical examination, diagnosis or treatment. Abnormal immunoglobulin levels need to be interpreted by your clinician with your symptoms, your medicines and your other results.