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Immunoglobulin A (IgA) in Serum or Plasma, Mass Concentration

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

This test measures the amount of Immunoglobulin A (IgA), a type of antibody in your blood. IgA helps protect your body from infections by preventing harmful substances from entering tissues.

Quick summary

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

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

Key facts at a glance

LOINC
6938-5
Short code
IgA Sal-mCnc
Synonyms
IgA Sal-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like frequent infections, unexplained rashes, or if they suspect conditions like IgA nephropathy (a kidney disease), common variable immunodeficiency (a weakened immune system), or other autoimmune disorders. It may also be used during pregnancy to check for certain infections or immune-related issues.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into a vein in your arm to draw blood. If you’re nervous, let your healthcare provider know—they can help make the process more comfortable.

What the Results Mean

IgA levels can vary based on health, age, and other factors. While reference ranges exist, they can differ by lab. Your results will be interpreted by a healthcare provider who will consider your overall health and medical history.

Common Conditions Monitored or Diagnosed

Low IgA levels may indicate immune system problems, such as common variable immunodeficiency or certain autoimmune diseases. High levels might be seen in some infections or inflammatory conditions, but this isn’t always the case.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgA Level

Frequently asked questions

What does a low IgA level mean?
A low IgA level may suggest an immune deficiency or an autoimmune disorder. Your doctor will review your symptoms and other test results to determine if further evaluation is needed, such as additional blood tests or specialized immune function studies.
Can IgA levels change with age?
Yes, IgA levels can fluctuate with age. Infants and young children may have lower IgA levels compared to adults. Pregnancy, chronic illnesses, or certain medications can also affect IgA levels, so results should always be discussed with your healthcare provider.
Is IgA testing always done with blood?
IgA testing is most commonly done with blood (serum or plasma), but it can also be measured in saliva or other bodily fluids depending on the clinical context. Always ask your provider about the specific test performed.
  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