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Immunoglobulin A (IgA) in Serum or Plasma by Immunoassay

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 fighting bacteria and viruses.

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
6779-3
Short code
IgA Ur IA-mCnc
Synonyms
IgA Ur IA-mCnc
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is Immunoglobulin A (IgA)?

IgA is a key part of your immune system, found in high concentrations in mucous membranes (like those in your nose, throat, and digestive tract). It helps prevent harmful substances from entering your body. IgA can also be detected in blood, where it plays a role in immune defense. Low or high levels may indicate certain health conditions.

Why Might You Need This Test?

Doctors may order an IgA test to check for immune system disorders, such as immunodeficiency, autoimmune diseases (like lupus or celiac disease), or to evaluate responses to treatments. It can also help diagnose conditions like IgA nephropathy (a kidney disease) or certain infections.

Common Reasons for Testing

Common reasons include unexplained infections, recurrent illnesses, symptoms of an overactive or underactive immune system, or when evaluating conditions linked to IgA, such as allergies or digestive issues.

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 blood is drawn. Wear comfortable clothing and bring any medications you’re currently taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgA Level

Frequently asked questions

How Does IgA Level Affect My Health?
Low IgA levels may suggest a weakened immune response, while very high levels could indicate certain immune disorders or overproduction of antibodies. Your doctor will interpret results in the context of your symptoms and medical history.
How Often Should I Get This Test?
The frequency depends on your health condition and treatment plan. Your doctor will determine how often to check IgA levels based on your specific needs.
What Are the Possible Results?
Results may be below normal (hypogammaglobulinemia), normal, or elevated. Your doctor will discuss what these results mean for you and whether further testing is needed.
  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