When is an IgG-IgA-IgM test ordered What do the antibody results mean

Immunoglobulins (antibodies) are a vital part of the immune system, commonly referred to by their abbreviations: IgG, IgA, and IgM. Measuring their levels in the blood helps assess immune function and diagnose a range of conditions such as chronic infections, autoimmune diseases, immune deficiencies, and certain types of cancer.In this guide from Daleeli Medical, we explain the purpose of these tests, what each antibody type indicates, when the test is needed, and how to interpret the results.

✅ What Are IgG, IgA, and IgM Antibodies?

1. IgG – Immunoglobulin G

The most abundant type of antibody in the body.
Serves as the main line of defense against long-term bacterial and viral infections.
Crosses the placenta from mother to fetus, providing passive immunity to newborns during the first few months of life.

2. IgA – Immunoglobulin A

Found primarily in mucosal secretions such as the respiratory, digestive, and urinary tracts.
Protects against localized infections in areas like the mouth, nose, intestines, and urinary tract.

3. IgM – Immunoglobulin M

The first antibody produced by the immune system in response to an acute infection.
Indicates recent or active infection and serves as an early marker of immune response.

When Is the IgG – IgA – IgM Test Ordered?

Doctors may recommend this test in the following situations:

✅ Recurrent or chronic infections
✅ Suspected immune deficiency
✅ Diagnosing or monitoring autoimmune diseases
✅ Evaluating immune response after vaccination
✅ Diagnosing certain cancers, such as multiple myeloma
✅ Screening newborns with suspected infections or delayed immune development

Normal Reference Ranges for Immunoglobulins

Note: Reference ranges may vary by lab, age, and gender.

Antibody	Approximate Normal Range
IgG	700 – 1600 mg/dL
IgA	70 – 400 mg/dL
IgM	40 – 230 mg/dL

⚠️ What Do the Results Mean?

Elevated Immunoglobulins

Antibody	Possible Causes of High Levels
IgG	Chronic infections, autoimmune diseases (e.g., lupus, rheumatoid arthritis), some cancers
IgA	Liver disease, chronic respiratory or gastrointestinal infections
IgM	Recent viral or bacterial infection, immune system disorders

Decreased Immunoglobulins

Antibody	Possible Causes of Low Levels
IgG	Primary or acquired immunodeficiency, kidney disorders, chemotherapy
IgA	Selective IgA deficiency, genetic immune disorders
IgM	Bone marrow failure, immune suppression, blood cancers

Antibodies and Infection Timing

In some cases, the test helps determine the stage of infection:

Result	Interpretation
IgM elevated only	Indicates a recent or active infection
IgG elevated only	Suggests a past infection or recovery
Both IgG and IgM elevated	Infection is in the healing phase or active immune response

Additional Tests Often Ordered

CBC (Complete Blood Count): Assesses white blood cell function
CRP / ESR: Detects acute or chronic inflammation
IgE testing: For allergy evaluation
Serum Protein Electrophoresis: Used to detect blood cancers or immune protein abnormalities

Tips Before the Test

No fasting is required.
Inform your doctor if you’re currently sick or have received a vaccine recently.
Avoid immunosuppressive medications (e.g., corticosteroids) unless advised by your doctor.

❓ Frequently Asked Questions (FAQ)

Does a high antibody level always indicate illness?
Not necessarily. Levels may rise temporarily after an infection or vaccination.

Can all immunoglobulin levels be low at once?
Yes, which may suggest a general immune deficiency.

Is the test painful?
No. It involves a standard blood sample.

How long do the results take?
Typically 24 to 48 hours.

✅ Summary

The IgG – IgA – IgM test is a valuable diagnostic tool that offers a comprehensive view of your immune system status. Abnormal levels help in identifying infections, immune disorders, and chronic conditions.

If you experience frequent infections or general fatigue, talk to your doctor about whether this test is right for you — early detection is key to better management and treatment.