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Serum or plasma substance concentration (qualitative) for Immunoglobulin A (IgA) by Immunoassay

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of Immunoglobulin A (IgA), a type of antibody in your blood. IgA helps protect your body from infections by fighting bacteria and viruses.

Quick summary

["IgA levels can help diagnose or monitor certain immune system conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
10086-7
Short code
ST I-Amp 6ms L-II
Synonyms
ST I-Amp 6ms L-II
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ekg
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

IgA is one of the key components of your immune system. It’s found in high concentrations in bodily fluids like saliva, tears, and mucus, but it also circulates in your bloodstream. This test specifically looks at the amount of IgA in your serum or plasma, which can vary depending on your health status and immune function.

Why Might You Need This Test?

Doctors may order an IgA test to check for conditions like immunodeficiency, certain autoimmune diseases, or to evaluate how your immune system is responding to treatments. It can also be part of screening for conditions like cystic fibrosis or other genetic disorders.

Common Reasons for Testing

If you have symptoms like frequent infections, unexplained fatigue, or a history of recurrent illnesses, your doctor might recommend this test to assess your immune response. It’s also used in some diagnostic workups for conditions affecting the immune system.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves drawing blood. Wear comfortable clothing and plan to stay near the testing site for a short time.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

IgA plays a critical role in protecting mucosal surfaces, and low levels can indicate underlying immune deficiencies or disorders. High levels might be seen in certain infections or inflammatory conditions, though this is less common. Always discuss your results with your healthcare provider for personalized interpretation.

Short name

IgA Screening/Confirmatory

Frequently asked questions

What does a low IgA level mean?
A low IgA level may suggest an immune deficiency, where your body struggles to produce enough antibodies to fight infections. This can affect your ability to fight off common illnesses like colds or respiratory infections. Conditions like Common Variable Immunodeficiency (CVID) or certain genetic disorders may also be associated with low IgA.
What does a high IgA level mean?
High IgA levels are less common but can sometimes be seen in certain infections, inflammatory diseases, or as part of a broader immune response. In some cases, it may be a normal variation, so results should always be reviewed by a healthcare provider.
Can IgA levels change with age?
Yes, IgA levels can vary with age. Infants and young children typically have lower IgA levels compared to adults. In adults, IgA levels can fluctuate due to infections, medications, or underlying health conditions. Your doctor will consider your overall health and medical history when interpreting results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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